FOR PUBLICATION

   UNITED STATES COURT OF APPEALS
        FOR THE NINTH CIRCUIT

VIRGINIA DUNCAN; PATRICK                  No. 23-55805
LOVETTE; DAVID MARGUGLIO;
CHRISTOPHER WADDELL;                        D.C. No.
CALIFORNIA RIFLE & PISTOL                3:17-cv-01017-
ASSOCIATION, INC., a California             BEN-JLB
corporation,

              Plaintiffs-Appellees,         OPINION

 v.

ROB BONTA, in his official capacity
as Attorney General of the State of
California,

              Defendant-Appellant.

       Appeal from the United States District Court
          for the Southern District of California
        Roger T. Benitez, District Judge, Presiding

      Argued and Submitted En Banc March 19, 2024
                San Francisco, California

                  Filed March 20, 2025
2                        DUNCAN V. BONTA


 Before: Mary H. Murguia, Chief Judge, and Sidney R.
Thomas, Susan P. Graber, Kim McLane Wardlaw, Richard
 A. Paez, Marsha S. Berzon, Sandra S. Ikuta, Andrew D.
    Hurwitz, Ryan D. Nelson, Patrick J. Bumatay and
          Lawrence VanDyke, Circuit Judges.

                  Opinion by Judge Graber;
                Concurrence by Judge Berzon;
                 Dissent by Judge R. Nelson;
                 Dissent by Judge Bumatay;
                 Dissent by Judge VanDyke;


                          SUMMARY *


        En Banc Procedures / Second Amendment

   The en banc court held that a California law banning the
possession of large-capacity magazines comports with the
Second Amendment, reversed the district court’s contrary
conclusion, and remanded with the instruction to enter
judgment in favor of the Attorney General of the State of
California.
   In 2016, the California legislature enacted Senate Bill
1446, which barred the possession of large-capacity
magazines as of July 1, 2017, and imposed a fine for failing
to comply. Later in 2016, California voters approved
Proposition 63, which subsumed Senate Bill 1446 and added
a provision that imposed a possible criminal penalty for

*
 This summary constitutes no part of the opinion of the court. It has
been prepared by court staff for the convenience of the reader.
                      DUNCAN V. BONTA                       3


unlawful possession of large-capacity magazines after July
1, 2017. 

(c).
    The en banc court affirmed its earlier rejection of
Plaintiffs’ Fifth Amendment takings claim in Duncan v.
Bonta (“Duncan V”), 

 (9th Cir.
2021) (en banc).
    Employing the methodology announced in New York
State Rifle & Pistol Ass’n v. Bruen, 

 (2022), the
en banc court concluded that California’s law comported
with the Second Amendment for two independent
reasons. First, the text of the Second Amendment does not
encompass the right to possess large-capacity magazines
because large-capacity magazines are neither “arms” nor
protected accessories. Second, even assuming that the text
of the Second Amendment encompasses the possession of
optional accessories like large-capacity magazines,
California’s ban on large-capacity magazines falls within the
Nation’s tradition of protecting innocent persons by
prohibiting especially dangerous uses of weapons and by
regulating components necessary to the firing of a firearm.
    Accordingly, the en banc court remanded this case to the
district court with the instruction to enter judgment in favor
of the California Attorney General.
    Concurring in full in the majority opinion, Judge Berzon,
joined by Chief Judge Murguia, and Judges Hurwitz, Paez,
S.R. Thomas, and Wardlaw, wrote separately to address
Judge VanDyke’s dissent, which includes a link to a video
that he recorded showing him handling several different
handguns and explaining his understanding of their
mechanics and operation. Judge Berzon pointed out two
problems with Judge VanDyke’s reliance on the
video: (1) The video is not part of his written dissent and it
4                      DUNCAN V. BONTA


includes facts outside the record. (2) Judge VanDyke has in
essence appointed himself as an expert witness in this case,
providing a factual presentation with the express aim of
convincing the readers of his view of the facts without
complying with any of the procedural safeguards that usually
apply to experts and their testimony, while simultaneously
serving on the panel deciding the case.
    Dissenting, Judge R. Nelson agreed with Judge
Bumatay’s dissent that the majority’s decision to reverse the
district court on the merits flouted Bruen. The majority’s
decision also spurned the statutory procedure for en banc
proceedings because, as explained in his dissent from the
order filed concurrently with this opinion, this en banc court
lacked statutory jurisdiction to decide this new appeal.
    Dissenting, Judge Bumatay, joined by Judges Ikuta, R.
Nelson, and VanDyke, would hold that nothing in the text,
or the country’s historical understanding of the Second
Amendment, warrants California’s magazine ban. Applying
the Bruen framework, California’s magazine ban is
presumptively unconstitutional because the plain text of the
Second Amendment protects the possession of magazines
capable of feeding more than ten rounds. California failed
to overcome the presumption of unconstitutionality where
California failed to identify a historical analogue that was
relevantly similar to a ban on these magazines. Accordingly,
he would hold that California’s magazine ban is
unconstitutional.
   Dissenting, Judge VanDyke agreed with Judge
Bumatay’s dissent, which demonstrated the correct approach
under the Second Amendment following Bruen, but wrote
separately to further highlight serious flaws in the majority’s
analysis. First, in determining that large-capacity magazines
                       DUNCAN V. BONTA                       5


are not part of the arms covered by the Second Amendment,
the majority erred by taking Bruen’s guidance to mean there
was an extensive first-step, arm-or-not inquiry. Whether a
firearm component is an inherent and “necessary” part of the
arm itself, or instead merely an “optional” and unnecessary
accessory to the arm, is a hopelessly indeterminable and
inadministrable distinction. Judge VanDyke included a
video in his dissent to illustrate the conceptual point, made
in the written portion of his dissent, that an “arm” is a broad
term covering an almost limitless variety of configurations
within that category. The Second Amendment cannot apply
only to firearms containing just those parts that a state like
California deems essential and necessary. Second, Judge
VanDyke agreed with Judge Bumatay that the majority erred
as a historical matter in assessing whether a ban on large-
capacity magazines is consistent with history and tradition.
     Finally, addressing Judge Berzon’s concurrence
criticizing the video portion of his dissent, Judge VanDyke
responded that his dissent is clearly evidenced by a written
disposition; and his criticism of the majority’s reliance on
the arms-accessory definition to decide this case is
fundamentally a conceptual one, not a factual one.
6                    DUNCAN V. BONTA


                       COUNSEL

Erin E. Murphy (argued), Paul D. Clement, and Matthew D.
Rowen, Clement & Murphy PLLC, Alexandria, Virginia;
Anna M. Barvir, Sean A. Brady, and C.D. Michel, Michel &
Associates PC, Long Beach, California; for Plaintiffs-
Appellees.
Michael J. Mongan (argued), Solicitor General, California
Department of Justice, San Francisco, California; Robert L.
Meyerhoff, Kevin J. Kelly, John D. Echeverria, and Robert
L. Meyerhoff, Deputy Attorneys General; R. Matthew Wise,
Supervising Deputy Attorney General; Mica L. Moore,
Deputy Solicitor General; Thomas S. Patterson, Senior
Assistant Attorney General; Helen H. Hong, Principal
Deputy Solicitor General; Rob Bonta, California Attorney
General; California Department of Justice, Los Angeles,
California; for Defendant-Appellant.
Amanda Hainsworth, Assistant Attorney General; Elizabeth
N. Dewar, State Solicitor; Andrea J. Campbell,
Massachusetts Attorney General; Office of the
Massachusetts Attorney General, Boston, Massachusetts;
Angela Cai, Deputy Solicitor General; Jeremy M.
Feigenbaum, Solicitor General; Matthew J. Platkin, New
Jersey Attorney General; Office of the New Jersey Attorney
General, Trenton, New Jersey; Kristin K. Mayes, Arizona
Attorney General, Office of the Arizona Attorney General,
Phoenix, Arizona; Philip J. Weiser, Colorado Attorney
General, Office of the California Attorney General, Denver,
Colorado; William Tong, Connecticut Attorney General,
Office of the Connecticut Attorney General, Hartford,
Connecticut; Kathleen Jennings, Delaware Attorney
General, Office of the Delaware Attorney General,
Wilmington, Delaware; Brian L. Schwalb, District of the
                     DUNCAN V. BONTA                    7


Columbia Attorney General, Office of the District of
Columbia Attorney General, Washington, D.C.; Anne E.
Lopez, Hawai'i Attorney General, Office of the Hawai'i
Attorney General, Honolulu, Hawai'i; Kwame Raoul,
Illinois Attorney General, Office of the Illinois Attorney
General, Chicago, Illinois; Aaron M. Frey, Maine Attorney
General, Office of the Maine Attorney General, Augusta,
Maine; Anthony G. Brown, Maryland Attorney General,
Office of the Maryland Attorney General, Baltimore,
Maryland; Dana Nessel, Michigan Attorney General, Office
of the Michigan Attorney General, Lansing, Michigan; Keith
Ellison, Minnesota Attorney General, Office of the
Minnesota Attorney General, St. Paul, Minnesota; Letitia
James, New York Attorney General, Office of the New York
Attorney General, New York, New York; Ellen F.
Rosenblum, Oregon Attorney General, Office of the Oregon
Attorney General, Salem, Oregon; Michelle A. Henry,
Pennsylvania Attorney General, Office of the Pennsylvania
Attorney General, Harrisburg, Pennsylvania; Peter F.
Neronha, Rhode Island Attorney General, Office of the
Rhode Island Attorney General, Providence, Rhode Island;
Charity R. Clark, Vermont Attorney General, Office of the
Vermont Attorney General, Montpelier, Vermont; Robert
W. Ferguson, Washington Attorney General, Office of the
Washington Attorney General, Olympia, Washington;
Joshua L. Kaul, Wisconsin Attorney General, Office of the
Wisconsin Attorney General, Madison, Wisconsin; for
Amici Curiae Massachusetts, New Jersey, Arizona,
Colorado, Connecticut, Delaware, The District of Columbia,
Hawai'i, Illinois, Maine, Maryland, Michigan, Minnesota,
New York, Oregon, Pennsylvania, Rhode Island, Vermont,
Washington, and Wisconsin.
8                   DUNCAN V. BONTA


Timothy C. Hester, Daniel Weltz, and Priya Leeds,
Covington & Burling LLP, Washington, D.C.; Douglas N.
Letter and Shira L. Feldman, Brady Center to Prevent Gun
Violence, Washington, D.C.; Esther Sanchez-Gomez,
Giffords Law Center to Prevent Gun Violence, San
Francisco, California; Ciara W. Malone, March for Our
Lives, New York, New York; for Amici Curiae Brady
Center to Prevent Gun Violence, Giffords Law Center to
Prevent Gun Violence, and March for Our Lives.
Priyanka G. Sen, William J. Taylor Jr., and Janet Carter,
Everytown Law, New York, New York; Freya Jamison,
Everytown Law, Washington, D.C.; for Amicus Curiae
Everytown for Gun Safety.
Joseph G.S. Greenlee and Cody J. Wisniewski, FPC Action
Foundation, Las Vegas, Nevada, for Amici Curiae FPC
Action Foundation, California Gun Rights Foundation, and
Center for Human Liberty.
Noel J. Francisco, Anthony J. Dick, and Harry S. Graver,
Jones Day, Washington, D.C.; Andrew E. Lelling, Jones
Day, Boston, Massachusetts; Matthew R. Modderman,
Jones Day, Cleveland, Ohio; Lawrence G. Keane, The
National Shooting Sports Foundation Inc., Washington,
D.C.; for Amicus Curiae The National Shooting Sports
Foundation Inc..
David H. Thompson and Peter A. Patterson, Cooper & Kirk
PLLC, Washington, D.C., for Amicus Curiae Firearm Policy
Coalition Inc..
Edward A. Paltzik, Meredith Lloyd, and Serge Krimnus,
Bochner PLLC, New York, New York, for Amicus Curiae
The Second Amendment Foundation.
                     DUNCAN V. BONTA                      9


Peter M. Torstensen Jr., Deputy Solicitor General; Christian
B. Corrigan, Solicitor General; Austin Knudsen, Montana
Attorney General; Office of the Montana Attorney General,
Helena, Montana; Joshua N. Turner, Acting Solicitor
General; Raul R. Labrador, Idaho Attorney General; Steve
Marshall, Alabama Attorney General; Office of the Alabama
Attorney General, Montgomery, Alabama; Treg Taylor,
Alaska Attorney General, Office of the Alaska Attorney
General, Anchorage, Alaska; Tim Griffin, Arkansas
Attorney General, Office of the Arkansas Attorney General,
Little Rock, Arkansas; Ashley Moody, Florida Attorney
General, Office of the Florida Attorney General,
Tallahassee, Florida; Christopher M. Carr, Georgia Attorney
General, Office of the Georgia Attorney General, Atlanta,
Georgia; Theodore E. Rokita, Indiana Attorney General,
Office of the Indiana Attorney General, Indianapolis,
Indiana; Brenna Bird, Iowa Attorney General, Office of the
Iowa Attorney General, Des Moines, Iowa; Kris Kobach,
Kansas Attorney General, Office of the Kansas Attorney
General, Topeka, Kansas; Daniel Cameron, Kentucky
Attorney General, Office of the Kentucky Attorney General,
Frankfort, Kentucky; Jeff Landry, Louisiana Attorney
General, Office of the Louisiana Attorney General, Baton
Rouge, Louisiana; Lynn Fitch, Mississippi Attorney
General, Office of the Mississippi Attorney General,
Jackson, Mississippi; Andrew Bailey, Missouri Attorney
General, Office of the Missouri Attorney General, Kansas
City, Missouri; Michael T. Hilgers, Nebraska Attorney
General, Office of the Nebraska Attorney General, Lincoln,
Nebraska; John M. Formella, New Hampshire Attorney
General, Office of the New Hampshire Attorney General,
Concord, New Hampshire; Drew H. Wrigley, North Dakota
Attorney General, Office of the North Dakota Attorney
10                   DUNCAN V. BONTA


General, Bismark, North Dakota; Dave Yost, Ohio Attorney
General, Office of the Ohio Attorney General; Columbus,
Ohio; Gentner F. Drummond, Oklahoma Attorney General,
Office of the Oklahoma Attorney General, Oklahoma City,
Oklahoma; Alan Wilson, South Carolina Attorney General,
Office of the South Carolina Attorney General, Columbia,
South Carolina; Marty J. Jackley, South Dakota Attorney
General, Office of the South Dakota Attorney General,
Pierre, South Dakota; Ken Paxton, Texas Attorney General,
Office of the Texas Attorney General, Austin, Texas; Jason
Miyares, Virginia Attorney General, Office of the Virginia
Attorney General, Richmond, Virginia; Patrick Morrisey,
West Virginia Attorney General, Office of the West Virginia
Attorney General, Charleston, West Virginia; Bridget Hill,
Wyoming Attorney General, Office of the Wyoming
Attorney General, Cheyenne, Wyoming; for Amici Curiae
Montana, Idaho, and 23 Other States.
Jeremiah L. Morgan, William J. Olson, and Robert J. Olson;
William J. Olson PC, Vienna, Virginia; John I. Harris III,
Schulman, LeRoy & Bennett PC, Nashville, Tennessee; for
Amici Curiae Gun Owners of America Inc., Gun Owners
Foundation, Gun Owners of California Inc., Heller
Foundation, Virginia Citizens Defense League, Tennessee
Firearms Association, America’s Future Inc., U.S.
Constitutional Rights Legal Defense Fund, and Conservative
Legal Defense and Education Fund.
John Cutonilli, Garrett Park, Maryland, for Amicus Curiae
John Cutonilli.
                      DUNCAN V. BONTA                     11

OPINION

GRABER, Circuit Judge:

    Mass shootings are devastating events for the victims,
their families, and the broader community. The first mass
shooting in the United States occurred in 1949, and they
have increased in frequency and in lethality, primarily
because of the widespread availability of modern firearm
technology: semi-automatic firearms equipped with large-
capacity magazines. A large-capacity magazine is a device
that, when attached to a semi-automatic firearm, allows a
shooter to fire more than ten rounds without pausing. A
large-capacity magazine has little function in armed self-
defense, but its use by mass shooters has exacerbated the
harm of those horrific events. Murderers who use large-
capacity magazines need not pause between shots until they
have fired 20, 30, or even 100 rounds. These pauses are
crucial. Victims and law enforcement personnel take
advantage of short pauses in firing to flee, take cover, and
fight back. A mass shooter’s use of large-capacity
magazines limits those precious opportunities.
    In 2016, following long traditions in our Nation of
protecting innocent persons by prohibiting especially
dangerous uses of weapons and by regulating components of
a firearm that are necessary to the firing of a firearm, the
California legislature and California’s voters banned the
possession of large-capacity magazines in order to address
mass shootings. Earlier, lesser measures, such as banning
the sale of those magazines, had proved both ineffective and
difficult to enforce.
   Plaintiffs challenge the constitutionality of California’s
ban. In Duncan v. Bonta (“Duncan V”), 

 (9th
12                    DUNCAN V. BONTA


Cir. 2021) (en banc), we upheld the law as consistent with
the Second Amendment and other constitutional guarantees.
After the Supreme Court introduced a new framework for
deciding Second Amendment challenges in New York State
Rifle & Pistol Ass’n v. Bruen, 

 (2022), the Court
vacated our decision and remanded for reconsideration.
Duncan v. Bonta, 

 (2022).
    Employing the methodology announced in Bruen and
recently applied in United States v. Rahimi, 

(2024), we again conclude that California’s law comports
with the Second Amendment, for two independent reasons.
First, the Founders protected the right to keep and bear
“Arms,” not a right to keep and bear “Arms and
Accoutrements,” a common expression at the time of the
Founding.       Large-capacity magazines are optional
accessories to firearms, and firearms operate as intended
without a large-capacity magazine. A large-capacity
magazine is thus an accessory or accoutrement, not an
“Arm” in itself. Possession of a large-capacity magazine
therefore falls outside the text of the Second Amendment.
See Bruen, 

 (instructing courts to ask whether
“the Second Amendment’s plain text covers an individual’s
conduct”).
     Second, even assuming that the text of the Second
Amendment encompasses the possession of an optional
accessory like a large-capacity magazine, California’s law
falls neatly within the Nation’s traditions of protecting
innocent persons by prohibiting especially dangerous uses of
weapons and by regulating components necessary to the
firing of a firearm. Plaintiffs understate the extent to which
our forebears regulated firearms to promote public safety.
California’s law is relevantly similar to such historical
regulations in both “how” and “why” it burdens the right to
                          DUNCAN V. BONTA                            13


armed self-defense. Like those historical laws, California’s
law restricts an especially dangerous feature of semi-
automatic firearms—the ability to use a large-capacity
magazine—while allowing all other uses of those firearms.
So far as California’s law is concerned, persons may own as
many bullets, magazines, and firearms as they desire; may
fire as many rounds as they like; and may carry their bullets,
magazines, and firearms wherever doing so is permissible.
The only effect of California’s law on armed self-defense is
the limitation that a person may fire no more than ten rounds
without pausing to reload, something rarely done in self-
defense. The justification for California’s law—to protect
innocent persons from infrequent but devastating events—is
also relevantly similar to the justifications for the historical
laws. California’s law is not a precise match to the historical
laws, “but it does not need to be.” Rahimi, 

.
By prohibiting only an especially dangerous use of a modern
weapon, the law “comport[s] with the principles underlying
the Second Amendment.” 

. We reverse the district
court’s contrary conclusion and remand with the instruction
to enter judgment in favor of Defendant Rob Bonta, Attorney
General of the State of California.
   FACTUAL AND PROCEDURAL BACKGROUND 1
    A. Large-Capacity Magazines
  A magazine is a device that automatically feeds
ammunition into a firearm whenever the shooter fires a


1
  Applying a bedrock principle of federal appellate review, we consider
only the factual record developed by the parties. Fed. R. App. P. 10.
With exceptions not relevant here, such as judicial notice, “we will not
consider facts outside the record developed before the district court.”
United States ex rel. Robinson Rancheria Citizens Council v. Borneo,
14                         DUNCAN V. BONTA




Inc., 

 (9th Cir. 1992). We therefore do not consider
factual information introduced in Judge VanDyke’s dissenting opinion.
   That dissent fundamentally misunderstands that legal rule by
comparing an appellate-judge-made video, which neither the district
court nor any party has ever seen or had an opportunity to comment on,
to our citation in Mai v. United States, 

 (9th Cir. 2020), of
publicly available scientific studies. Dissent by J. VanDyke at 144. The
legal issue in Mai required us to assess whether adequate scientific
evidence fairly supported a legislative judgment. 

. The
plaintiff’s primary argument—before us and before the district court—
was that we should agree with the Sixth Circuit’s analysis of the
scientific evidence in Tyler v. Hillsdale County Sheriff’s Department,

 (6th Cir. 2016) (en banc). Both parties in Mai discussed
Tyler at length. In our opinion, we cited and discussed, as had the Sixth
Circuit, the primary scientific study relevant to the legal issue. Mai, 952
F.3d at 1117–18; Tyler, 837 F.3d at 695–96. Our discussion of the
publicly available scientific study that underpinned the parties’ primary
dispute was entirely proper in the context of the legal issue at hand.
Indeed, the parties had asked us to assess the scientific evidence.
Presumably for that reason, neither the parties nor a single dissent from
denial of rehearing en banc asserted that we had cited facts outside the
record developed before the district court. Mai v. United States, 

 (9th Cir. 2020) (order) (Collins, J., dissenting from the
denial of reh’g en banc); 

 at 1083–97 (Bumatay, J., dissenting from
the denial of reh’g en banc); 

 at 1097–1106 (VanDyke, J., dissenting
from the denial of reh’g en banc). By sharp contrast to that publicly
available study, the judge-made video here clearly contains facts outside
the record developed before the district court.
  Judge VanDyke’s dissenting opinion here also cites an offhand
footnote in Mai. In that footnote, we took judicial notice of the fact that
evidence of a certain sort exists in other contexts, we cited a report by
the American Cancer Society, and we observed that no similar evidence
existed in the context relevant to the case. Mai, 

 n.7.
Judicial notice was appropriate because we took notice of the existence
of evidence of a particular sort, regardless of its accuracy. Von Saher v.
Norton Simon Museum of Art at Pasadena, 

 (9th Cir.
2010). Judicial notice plainly does not authorize the judge-made video
contained in Judge VanDyke’s dissenting opinion.
                      DUNCAN V. BONTA                     15


bullet. Although some magazines are permanently affixed
to a firearm, most magazines are detachable. Ocean State
Tactical, LLC v. Rhode Island, 

 (1st Cir.
2024), petition for cert. filed, No. 24-131 (U.S. Aug. 2,
2024). When a magazine feeds a semi-automatic firearm,
the shooter may continue to fire without pause and without
taking any action other than pulling the trigger to fire
successive rounds. A shooter thus may fire, repeatedly and
without meaningful pause, all bullets in the magazine.
    Many jurisdictions, including California, define “large-
capacity magazine” to include any magazine or similar
automatic feeding device that can hold more than ten rounds
of ammunition. E.g., 

; 

-202w(a)(1); 

(c). Large-
capacity magazines thus allow a shooter to fire more than ten
rounds without reloading.
    Once a magazine is empty, a shooter may reload bullets
into the magazine or may attach a different magazine to the
firearm. It takes anywhere from a few to ten seconds for a
person to change magazines, depending on the shooter’s
skill and the surrounding circumstances.
    For those firearms that accept magazines, manufacturers
often include large-capacity detachable magazines as part of
the standard package when the firearm is purchased. “Most
pistols are manufactured with magazines holding ten to
seventeen rounds, and many popular rifles are manufactured
with magazines holding twenty or thirty rounds.” Kolbe v.
Hogan, 

 (4th Cir. 2017) (en banc),
abrogated in other part by Bruen, 

. Although data
are imprecise, experts estimate that approximately half of
privately owned magazines hold more than ten rounds.
16                    DUNCAN V. BONTA


    A large-capacity magazine—which enables a shooter to
fire more than ten bullets rapidly and without reloading—
has almost no utility in the lawful defense of the home, but
it has devastating effects in mass shootings. A shooter
equipped with a large-capacity magazine may kill and injure
many people in rapid succession, not only because the
shooter can fire many bullets quickly but also because the
shooter can fire without pausing to reload. Those pauses are
crucial because they allow intended victims and law
enforcement personnel to flee, take cover, and fight back.
More than twice as many people have been killed or injured
in mass shootings that involved a large-capacity magazine
than in mass shootings that involved a smaller-capacity
magazine. And in the past half-century, large-capacity
magazines have been used in about three-quarters of gun
massacres with ten or more deaths and in every gun massacre
with twenty or more deaths.
     B. California’s Ban
     In 1994, Congress banned the possession or transfer of
large-capacity magazines. 

,

, 1998–2000 (1994). Like California’s law,
the federal statute applied to a magazine “that has a capacity
of . . . more than 10 rounds of ammunition.” 

 The federal
ban exempted magazines that were legally possessed before
the date of enactment. 

 The law expired ten years later,
in 2004. 

 § 110105(2).
    California began regulating large-capacity magazines in
2000, prohibiting their manufacture, importation, or sale in
the state. 

(a)(2) (2000). After the
expiration of the federal ban, California strengthened its law
in 2010 and again in 2013 by, among other things,
prohibiting the purchase or receipt of large-capacity
                       DUNCAN V. BONTA                       17


magazines. 

(a) (2013). But
possession of large-capacity magazines remained legal, and
law enforcement officers reported to the California
legislature that enforcement of the existing laws was “very
difficult.”
    In 2016, the California legislature enacted Senate Bill
1446, which barred possession of large-capacity magazines
as of July 1, 2017, and imposed a fine for failing to comply.
2016 Cal. Stat. ch. 58, § 1. Later in 2016, voters in
California approved Proposition 63, also known as the
Safety for All Act of 2016, which subsumed Senate Bill
1446 and added provisions that imposed a possible criminal
penalty of imprisonment for up to a year for unlawful
possession of large-capacity magazines after July 1, 2017.

(c). Proposition 63 declared that
large-capacity magazines “significantly increase a shooter’s
ability to kill a lot of people in a short amount of time.” Cal.
Prop. 63 § 2(11). “No one except trained law enforcement
should be able to possess these dangerous ammunition
magazines,” and the existing law’s lack of a ban on
possession constituted a “loophole.” Id. § 2(12). The law’s
stated purpose is “[t]o make it illegal in California to possess
the kinds of military-style ammunition magazines that
enable mass killings like those at Sandy Hook Elementary
School; a movie theater in Aurora, Colorado; Columbine
High School; and an office building at 101 California Street
in San Francisco, California.” Id. § 3(8).
   California law defines a “large-capacity magazine” as
any ammunition-feeding device with the capacity to accept
18                     DUNCAN V. BONTA


more than ten rounds, but does not include any of the
following:

       (a) A feeding device that has been
       permanently altered so that it cannot
       accommodate more than 10 rounds.
       (b) A .22 caliber tube ammunition feeding
       device.
       (c) A tubular magazine that is contained in a
       lever-action firearm.

. The ban on possession of large-
capacity magazines exempts persons such as active or retired
law enforcement officers and security guards for armored
vehicles. 

 §§ 32400–55. The law requires any current,
non-exempt possessor of a large-capacity magazine to
(1) remove it from the state, (2) sell it to a licensed dealer,
(3) turn it in to law enforcement for destruction, or
(4) permanently alter it so that it can accept no more than ten
rounds. Id. §§ 16740(a), 32310(d).
    The District of Columbia and thirteen other states have
imposed similar restrictions on large-capacity magazines.

, 302; 

-
202w; Del. Code tit. 11, §§ 1468–69; 

-
2506.01(b); 

(c); 720 Ill. Comp. Stat.
5/24-1.10; 

(b); 

, 131(a), 131M; N.J. Stat. Ann.
§§ 2C:39-1(y), 39-3(j), 39-9(h); 

,
265.02(8); 2022 Oregon Ballot Measure 114, § 11; R.I. Gen.
Laws §§ 11-47.1-2(2), 11-47.1-3; 

; 

, 9.41.370.
                       DUNCAN V. BONTA                       19


   C. Procedural History
    Plaintiffs own, or represent those who own, large-
capacity magazines, and they do not want to comply with
California’s law. Plaintiffs brought this action in 2017,
arguing that California’s prohibition on the possession of
large-capacity magazines violates the Second Amendment,
the Fifth Amendment’s Takings Clause, and the Fourteenth
Amendment’s Due Process Clause.
    The district court preliminarily enjoined Defendant from
enforcing the law, holding that Plaintiffs were likely to
succeed on their Second Amendment and Takings Clause
claims. Duncan v. Becerra (“Duncan I”), 

 (S.D. Cal. 2017). On appeal, a divided panel affirmed
the preliminary injunction, concluding that the district court
did not abuse its discretion in holding that Plaintiffs had
shown a likelihood of success on their claims. Duncan v.
Becerra (“Duncan II”), 

, 221–22 (9th Cir.
2018) (unpublished); see 

 at 223–26 (Wallace, J.,
dissenting) (voting to reverse the preliminary injunction).
    In 2019, the district court granted summary judgment to
Plaintiffs on the Second Amendment and takings claims, and
the court permanently enjoined enforcement of the law.
Duncan v. Becerra (“Duncan III”), 

(S.D. Cal. 2019). On appeal, another divided panel affirmed
the summary judgment as to the Second Amendment claim.
Duncan v. Becerra (“Duncan IV”), 

 (9th Cir.
2020); see 

 at 1169–76 (Lynn, D.J., dissenting) (stating
that she would reject the Second Amendment claim). A
majority of active judges voted to rehear the case en banc.
Duncan v. Becerra, 

 (9th Cir. 2021) (order).
   Sitting as the en banc court, we applied the two-part test
adopted by all circuit courts at the time, reversed the district
20                     DUNCAN V. BONTA


court’s judgment, and remanded with the instruction to enter
judgment for Defendant. Duncan V, 

. After
our ruling, the Supreme Court decided Bruen, announcing a
new framework for deciding Second Amendment
challenges. The Supreme Court then granted certiorari,
vacated the judgment, and remanded for further
consideration in light of Bruen. Duncan, 

.
We, in turn, remanded the case to the district court to
consider, in the first instance, the effect of Bruen on the
Second Amendment claim. Duncan v. Bonta, 

(9th Cir. 2022) (en banc) (order).
    On remand, the district court declined to reopen
discovery or to conduct an evidentiary hearing or trial.
Instead, the court again granted summary judgment to
Plaintiffs on the Second Amendment claim and permanently
enjoined Defendant from enforcing the law. Duncan v.
Bonta (“Duncan VI”), 

 (S.D. Cal.
2023). Defendant timely appealed, and the en banc court
chose, pursuant to Ninth Circuit General Order 3.6(b), to
address the new appeal. We granted Defendant’s motion to
stay the permanent injunction pending our resolution of this
appeal. Duncan v. Bonta (“Duncan VII”), 

 (9th
Cir. 2023) (en banc) (order).
   After we heard oral argument, the Supreme Court
decided Rahimi, 

.
                        DISCUSSION
     A. Takings Claim
    The Fifth Amendment provides, “nor shall private
property be taken for public use, without just compensation.”
U.S. Const. amend. V. Plaintiffs assert that, on its face, the
statute effects a taking because it requires Plaintiffs either to
                       DUNCAN V. BONTA                       21


(1) modify any large-capacity magazines so that they accept
ten or fewer rounds, (2) sell them, (3) move them out of the
state, or (4) turn them over to state officials for destruction.

(a), 32310(d). We rejected that
claim in Duncan V, 19 F.4th at 1111–13. On remand, the
district court did not consider the takings claim but, on
appeal, Plaintiffs ask us to affirm on the alternative ground
of a takings violation.
    The Supreme Court’s decision in Bruen had no effect on
our takings analysis, nor have any other intervening
decisions aided Plaintiffs’ position. We adopt and affirm our
earlier rejection of this claim. 

 at 1111–13. Our ruling is
in accord with decisions by the First and Third Circuits. See
Ocean State, 95 F.4th at 52–53 (holding that the plaintiffs
were unlikely to succeed on a takings challenge to Rhode
Island’s ban on large-capacity magazines); Ass’n of N.J.
Rifle & Pistol Clubs, Inc. v. Att’y Gen. N.J. (“ANJRPC”),

, 124–25 (3d Cir. 2018) (rejecting a takings
challenge to New Jersey’s ban on large-capacity magazines),
abrogated in other part by Bruen, 

.
   B. Second Amendment Claim
    The Second Amendment provides: “A well regulated
Militia, being necessary to the security of a free State, the
right of the people to keep and bear Arms, shall not be
infringed.” U.S. Const. amend. II. The Amendment creates
an individual right to keep and bear arms for self-defense.
District of Columbia v. Heller, 

(2008). The right applies against States via the Fourteenth
Amendment. McDonald v. City of Chicago, 

 (2010) (plurality opinion).
    The Supreme Court has instructed that, “[l]ike most
rights, the right secured by the Second Amendment is not
22                     DUNCAN V. BONTA


unlimited.” Heller, 

. It is “not a right to keep
and carry any weapon whatsoever in any manner whatsoever
and for whatever purpose.” 

 For example, the Second
Amendment protects only those weapons “in common use at
the time.” 

 at 627 (quoting United States v. Miller, 

 (1939)).
   In Bruen, the Supreme Court announced the appropriate
general methodology for deciding Second Amendment
challenges to state laws:

       When the Second Amendment’s plain text
       covers an individual’s conduct, the
       Constitution presumptively protects that
       conduct. The government must then justify
       its regulation by demonstrating that it is
       consistent with the Nation’s historical
       tradition of firearm regulation.

.
     Applying that methodology to California’s ban on large-
capacity magazines, we reject Plaintiffs’ Second
Amendment challenge for two independent reasons. First,
the plain text of the Amendment protects the right to bear
“Arms,” not accessories to firearms that are neither arms
themselves nor necessary to the ordinary functioning of a
firearm. Because large-capacity magazines are neither
weapons nor accessories that are necessary to the operation
of a weapon, the Second Amendment’s plain text does not
protect possession of large-capacity magazines. Second,
even assuming that California’s law implicates the text of the
Second Amendment, the ban on large-capacity magazines
fits comfortably within our “historical tradition of firearm
regulation,” Rahimi, 

 (quoting Bruen, 597
                       DUNCAN V. BONTA                       23


U.S. at 17). California’s law fits within the traditions of
protecting innocent persons by restricting a component
necessary to the firing of a firearm and by restricting
especially dangerous uses of weapons when those uses have
proved particularly harmful.
   1. Large-Capacity Magazines Are Neither “Arms” Nor
      Protected Accessories.
    We first examine “whether the plain text of the Second
Amendment protects [Plaintiffs’] proposed course of
conduct.” Bruen, 

. Plaintiffs assert that their
proposed conduct—possessing large-capacity magazines—
implicates the text of the Second Amendment because, in
their view, large-capacity magazines are arms commonly
chosen for the purpose of self-defense. Defendant raises
several distinct arguments to the contrary: large-capacity
magazines are not “Arms” within the meaning of the Second
Amendment; they are not in common use for self-defense;
they are most useful in military service; and they are
dangerous and unusual. See, e.g., Hanson v. District of
Columbia, 

, 14 (D.D.C. 2023) (holding that
large-capacity magazines do not fall within the text of the
Second Amendment because “they are most useful in
military service”), aff’d on other grounds, 

(D.C. Cir. 2024); see also Bianchi v. Brown, 

,
461 (4th Cir. 2024) (en banc) (“[T]he AR-15 is a combat rifle
that is both ill-suited and disproportionate to self-defense. It
thereby lies outside the scope of the Second Amendment.”),
petition for cert. filed sub nom. Snope v. Brown, No. 24-203
(U.S. Aug. 21, 2024). Because we conclude that large-
capacity magazines are not “Arms” within the meaning of
the Second Amendment, we need not, and do not, reach
24                         DUNCAN V. BONTA


Defendant’s alternative arguments pertaining to the text of
the Second Amendment. 2
    The text of the Second Amendment encompasses “the
right of the people to keep and bear Arms.” U.S. Const.
amend. II. We must look to history to understand the
meaning of “Arms.” Bruen, 

. The Second
Amendment’s “reference to ‘arms’ does not apply ‘only to
those arms in existence in the 18th century.’” 

(brackets omitted) (quoting Heller, 

). “[T]he
Second Amendment extends, prima facie, to all instruments
that constitute bearable arms, even those that were not in
existence at the time of the founding.” 

 (quoting Heller,

) (internal quotation marks omitted). “Thus,
even though the Second Amendment’s definition of ‘arms’

2
  “There is no consensus on whether the common-use issue” is a
threshold, textual inquiry or a historical inquiry. Hanson, 120 F.4th at
232 n.3 (quoting Bevis v. City of Naperville, 

 (7th
Cir. 2023), cert. denied sub nom. Harrel v. Raoul, 

(2024)). In United States v. Alaniz, 

 (9th Cir. 2023), we
placed this question in the initial, textual determination. 

. Judge Bumatay’s dissenting opinion now argues, in direct contrast
to his view less than eighteen months ago, that the inquiry belongs
instead in the historical analysis. Compare Dissent by J. Bumatay at 92–
95 (arguing that the inquiry belongs in the historical analysis), with
Duncan VII, 

 (Bumatay, J., dissenting) (placing the
inquiry clearly in the textual category). Both views find some support in
the text of Bruen. See Bianchi, 111 F.4th at 501–02 (Richardson, J.,
dissenting) (describing the support for both approaches). Because we do
not reach the issue as presented by Defendant, we need not and do not
address the issue here; therefore, Alaniz remains good law. To the extent
that Plaintiffs’ argument about ownership statistics overlaps with, or is
identical to, an “in common use today for self-defense” argument, we
give Plaintiffs the benefit of the doubt and, out of an abundance of
caution, resolve this question in the historical analysis, where Defendant
bears the burden of proof. See Part B-2-d, below.
                       DUNCAN V. BONTA                       25


is fixed according to its historical understanding, that general
definition covers modern instruments that facilitate armed
self-defense.” 

    “The 18th-century meaning [of ‘Arms’] is no different
from the meaning today.” Heller, 

.
Consistent with modern usage, dictionaries from the 18th
century defined the term as encompassing “weapons of
offence, or armour of defence” and “any thing that a man
wears for his defence, or takes into his hands, or useth in
wrath to cast at or strike another.” 

 (quoting, first, 1
Dictionary of the English Language 106 (4th ed.) (reprinted
1978) and, second, 1 A New and Complete Law Dictionary
(1771)). The term includes commonplace weapons and is
not limited to military weapons. 

 The meaning of “Arms”
thus broadly includes nearly all weapons used for armed
self-defense.
      The scope of the Second Amendment is broad in a
second sense as well. As we recognized a decade ago, for
the right to bear arms to have meaning, the Amendment’s
text must carry an implicit, corollary right to bear the
components or accessories necessary for the ordinary
functioning of a firearm. See Jackson v. City & County of
San Francisco, 

 (9th Cir. 2014) (holding
that, unless understood to protect the corollary right to
possess ammunition, “the right to bear arms would be
meaningless”), abrogated in other part by Bruen, 

;
see also Fyock v. Sunnyvale, 

 (9th Cir.
2015) (holding that the Second Amendment encompasses a
“corollary” right to possess components “necessary to render
. . . firearms operable”), abrogated in other part by Bruen,

; cf. B & L Prods., Inc. v. Newsom, 

,
118 (9th Cir. 2024) (reaffirming, after Bruen, that “unless
the right to acquire firearms receives some Second
26                    DUNCAN V. BONTA


Amendment protection, the right to keep and bear firearms
would be meaningless” (emphasis omitted)); 

 (“Ancillary
rights are protected to the extent necessary to serve [lawful
purposes such as self-defense]; otherwise, the Second
Amendment is not implicated by restraints on such rights.”).
A complete ban on ammunition thus would implicate the
Second Amendment, as likely would a ban on, for example,
firearm triggers.
    But the text of the Second Amendment also reveals an
important limit on the scope of the right. In particular, the
Amendment protects only the right to bear Arms. At the
time of ratification, a clear distinction was recognized
between weapons themselves, referred to as “arms,” and
accessories of weaponry, referred to as “accoutrements.”
Common accoutrements included flint, scabbards, holsters,
and ammunition containers such as cartridge cases and
cartridge boxes. “Accoutrements” were distinct from
“arms.” For example, the Continental Congress promised to
pay States for “[e]very horse and all arms and
accoutrements, which shall be taken, by the enemy in
action.” 2 Public Papers of George Clinton 828 (Wynkoop
Hallenbeck Crawford Co. ed., 1900) (emphasis added).
Similarly, the Duke of Wellington described the need “to
collect the wounded and their arms and accoutrements” from
a battlefield. 10 The Dispatches of Field Marshal the Duke
of Wellington (1799-1818) 495 (Murray ed., 1838)
(emphasis added).       Hundreds of examples from the
Founding era describe arms and accoutrements as separate,
distinct items of military gear, and the phrase “arms and
accoutrements” was common.
   By choosing to protect the right to bear “arms,” not
“arms and accoutrements,” the Founders constrained the
scope of the Second Amendment. The term “Arms” thus
                         DUNCAN V. BONTA                          27


encompasses most weapons used in armed self-defense, and
the Second Amendment necessarily protects the components
necessary to operate those weapons. But it does not protect
the right to bear accoutrements.
    Applying those principles here, California’s ban on
large-capacity magazines does not fall within the plain text
of the Second Amendment. A large-capacity magazine is a
box that, by itself, is harmless. It cannot reasonably be
described as an item that a person “takes into his hands, or
useth in wrath to cast at or strike another.” Heller, 

. Nor can it be reasonably described, by itself, as a
“weapon[] of offence, or armour of defence.” 

 Without
an accompanying firearm, a large-capacity magazine is
benign, useless in combat for either offense or defense.
Large-capacity magazines thus fall clearly within the
category of accessories, or accoutrements, rather than arms.
    That straightforward conclusion does not end our
analysis, though. We also must consider whether the
possession of large-capacity magazines falls within the
corollary right to possess accessories that are necessary for
the ordinary operation of a protected weapon. 3 Some (but
not all) firearms require the use of a magazine in order to
operate. For that reason, the Second Amendment’s text
necessarily encompasses the corollary right to possess a
magazine for firearms that require one, just as it protects the
right to possess ammunition and triggers. Otherwise, the
right to bear arms, including firearms that require the use of
a magazine, would be diminished.



3
 We assume for purposes of analysis that Plaintiffs intend to possess
weapons that are protected by the text of the Second Amendment.
28                     DUNCAN V. BONTA


    But a large-capacity magazine—the only type of
accessory regulated by California—is not necessary to
operate any firearm. Most firearms that accept detachable
magazines can be equipped with a large-capacity magazine,
but the record contains no example of a firearm that requires
a large-capacity magazine to function normally. To the
contrary, firearms that accept magazines operate as intended
when equipped with magazines containing ten or fewer
rounds. Accordingly, the Second Amendment’s plain text
does not encompass a right to possess large-capacity
magazines.
    Plaintiffs point out that a magazine is attached to the
firearm when the shooter fires a shot. Unlike some other
accessories, then, a magazine is an integral part of the firing
mechanism of some firearms. Plaintiffs contend that, for
that reason, the Second Amendment’s text necessarily
encompasses a right to possess a magazine for firearms that
require one. We agree, for the reasons described above, that
the Second Amendment’s text encompasses a right to
possess a magazine in that circumstance.
    Plaintiffs further contend, however, that the
Amendment’s text also encompasses a right to possess a
large-capacity magazine because, when a shooter chooses to
use a large-capacity magazine, it, too, is attached to the
firearm when the shooter fires a shot. We reject that
reasoning for two independent reasons. First, the function
of the large-capacity magazine is completed once the
magazine automatically places a new round into the
chamber. The large capacity of the magazine plays no role
in the firing mechanism of the firearm. In this way, a large-
capacity magazine is no different than other items that hold
additional ammunition, such as cartridge boxes and belts that
                      DUNCAN V. BONTA                       29


hold bullets, yet were          classified   historically   as
accoutrements, not arms.
    Second, and more fundamentally, Plaintiffs’ contention
misunderstands the relevant test. The proper inquiry for an
item that is not an arm itself is whether the component or
accessory is necessary to the ordinary operation of the
weapon, not whether, when one voluntarily chooses to use
an optional accessory, the accessory is attached to the
weapon. Many optional accessories—such as a high-
powered scope for a rifle, a gun sling, or a silencer—may be
attached to a firearm without necessarily falling within the
scope of the text of the Second Amendment. See, e.g.,
United States v. Cox, 

 (10th Cir. 2018)
(“A silencer is a firearm accessory; it’s not a weapon in
itself.”).
    A large-capacity magazine undoubtedly provides a
benefit for a shooter: it allows firing an eleventh round or
more without having to pause for a few seconds to reload.
But the enhancement of a person’s ability to fight or to
defend is a fundamental attribute of any accessory for a
weapon. A sword sheathed in a scabbard, a rifle equipped
with a high-powered scope, a six-shooter nestled loosely in
a holster—all are superior in some way to the same weapons
without the accessory. The mere fact that an accessory
enhances an attribute of a weapon does not bring the
accessory within the scope of the Second Amendment’s text.
    The Founders limited the Second Amendment’s
protection to the right to bear arms, not the broader right to
bear arms and accoutrements. We must respect that
limitation, just as we must respect the Founders’ choice to
protect the right to bear a broad range of arms. Cf. Rahimi,
602 U.S. at 691–92 (“[T]he Second Amendment permits
30                    DUNCAN V. BONTA


more than just those regulations identical to ones that could
be found in 1791. Holding otherwise would be as mistaken
as applying the protections of the right only to muskets and
sabers.”). Because the text of the Second Amendment does
not encompass the right to possess large-capacity magazines,
we hold that Plaintiffs’ Second Amendment claim fails. See
Or. Firearms Fed’n v. Kotek, 

, 911–13
(D. Or. 2023) (explaining why large-capacity magazines are
not “Arms” within the meaning of the Second Amendment),
appeals filed, Nos. 23-35478, 23-35479 (9th Cir. July 17,
2023); Ocean State Tactical, LLC v. Rhode Island, 

, 384–88 (D.R.I. 2022) (same), aff’d on other
grounds 

; cf. Bevis, 

 (concluding,
for a different reason, that large-capacity magazines are not
“Arms”).
     2. California’s Ban on Large-Capacity Magazines Falls
        Within the Nation’s Historical Tradition of Firearm
        Regulation.
    Plaintiffs’ argument fares no better even if we assume
that their proposed conduct falls within the plain text of the
Second Amendment.
    In Bruen, the Supreme Court explained that a
government must justify a regulation of firearms by
demonstrating that it falls within the Nation’s tradition of
regulating weapons. 

. A court’s assessment
of whether a law comports with a tradition defined by
historical laws “will often involve reasoning by analogy.”

. “[D]etermining whether a historical regulation is
a proper analogue for a distinctly modern firearm regulation
requires a determination of whether the two regulations are
‘relevantly similar.’” 

 at 28–29. The two most important
considerations are “how and why the regulations burden a
                       DUNCAN V. BONTA                      31


law-abiding citizen’s right to armed self-defense.” 

.
More specifically, we must consider whether the regulations
“impose a comparable burden on the right of armed self-
defense and whether that burden is comparably justified.”

    Analogical reasoning is “neither a regulatory
straightjacket nor a regulatory blank check.” 

. The
government must “identify a well-established and
representative historical analogue, not a historical twin.” 

So even if a modern regulation is not a “dead ringer” for a
historical analogue, “it still may be analogous enough to pass
constitutional muster.” 

    The Court gave an example of the longstanding laws
prohibiting the carry of firearms in “sensitive places,” such
as legislative assemblies and courthouses. 

 Although few
such historical laws existed, the Court “assume[d] it settled
that these locations were ‘sensitive places’ where arms
carrying could be prohibited consistent with the Second
Amendment.” 

 “And courts can use analogies to those
historical regulations of ‘sensitive places’ to determine that
modern regulations prohibiting the carry of firearms in new
and analogous sensitive places are constitutionally
permissible.” 

 But those historical laws do not justify the
conclusion that entire cities are “sensitive places” simply
because people congregate there and law enforcement is
present. 

 at 30–31. That analogy would be “far too
broad[],” because it “would eviscerate the general right to
publicly carry arms for self-defense.” 

.
    The Court emphasized that the historical analogies both
in Bruen and in Heller were “relatively simple to draw.” 

. Heller concerned the District of Columbia’s
“complete prohibition” on handguns, 

, and
32                    DUNCAN V. BONTA


Bruen concerned New York’s “may issue” licensing scheme,

. In those cases, the perceived societal
problems—firearm violence in densely populated
communities and the need to regulate who may possess a
firearm—had existed since the Founding, and the
regulations that the governments chose to impose—a ban on
handguns and a “may issue” licensing scheme—were ones
“that the Founders themselves could have adopted” to
confront those problems. Bruen, 

. “[W]hen a
challenged regulation addresses a general societal problem
that has persisted since the 18th century,” then a modern
regulation likely is inconsistent with the Second Amendment
if the Founders either addressed the problem “through
materially different means” or did not enact “a distinctly
similar historical regulation.” 

.
   By contrast, the Court explained, “cases implicating
unprecedented societal concerns or dramatic technological
changes may require a more nuanced approach.” 

.
“The regulatory challenges posed by firearms today are not
always the same as those that preoccupied the Founders in
1791 or the Reconstruction generation in 1868.” 

“Although its meaning is fixed according to the
understandings of those who ratified it, the Constitution can,
and must, apply to circumstances beyond those the Founders
specifically anticipated.” 

.
    When considering historical sources, “not all history is
created equal.” 

. Regulations enacted close to the
time of ratification are the most relevant, because
“[c]onstitutional rights are enshrined with the scope they
were understood to have when the people adopted them.” 

(quoting Heller, 554 U.S. at 634–35) (emphasis in Bruen).
Historical evidence that long predates, or long postdates, the
date of ratification is less illuminating, particularly if it
                           DUNCAN V. BONTA                             33


contradicts the text of the Second Amendment or evidence
from the time of the ratification. 4 

 at 34–37.
    The Supreme Court recently applied Bruen’s framework
in Rahimi, 

. Eight justices joined the majority
opinion, with only Justice Thomas, the author of Bruen,
dissenting. 

. Rahimi concerned a challenge to 

(g)(8), which criminalizes the possession of a
firearm by a person who is subject to a domestic-violence
restraining order. 

 at 688–89. The Court had “no trouble”
concluding that § 922(g)(8), as applied to Rahimi, was
consistent with the Second Amendment. Id. at 700.
    The Court began by noting that some courts had
misunderstood Bruen’s methodology and had applied it too
stringently. Id. at 691. The Court emphasized that the
methodology was “not meant to suggest a law trapped in
amber.” Id. “[T]he Second Amendment permits more than
just those regulations identical to ones that could be found in
1791.” Id. at 691–92.
   Rahimi summarized the methodology as follows: “[T]he
appropriate analysis involves considering whether the
challenged regulation is consistent with the principles that
underpin our regulatory tradition.” Id. at 692. “Why and
how the regulation burdens the right are central to this


4
  The Court has made clear that at least one relevant date of ratification
is 1791, the year in which the States ratified the Second Amendment.
Bruen, 

. The Second Amendment’s protections apply to
the States via the Fourteenth Amendment, which was ratified in 1868.

 The Court twice has reserved whether, for laws enacted by States,
another relevant date is 1868. 

; Rahimi, 

 n.1. We
need not address that issue here, because the relevant historical
traditions, discussed below, all began at the time of the Founding or
earlier.
34                    DUNCAN V. BONTA


inquiry.” 

 “And when a challenged regulation does not
precisely match its historical precursors, ‘it still may be
analogous enough to pass constitutional muster.’” 

(quoting Bruen, 

). “The law must comport
with the principles underlying the Second Amendment, but
it need not be a ‘dead ringer’ or a ‘historical twin.’” 

(quoting Bruen, 

).
    Applying that methodology to § 922(g)(8), Rahimi
looked to “two distinct legal regimes.” Id. at 694. The first
regime consisted of surety laws, laws that required a person
to post a bond that would be forfeited if the person later
breached the peace. Id. at 695–97. Those laws sometimes
applied to persons who carried dangerous weapons publicly.
Id. at 696. The second regime consisted of “going armed”
laws, laws that prohibited “riding or going armed, with
dangerous or unusual weapons, to terrify the good people of
the land.” Id. at 697 (quoting 4 Blackstone 149) (brackets
omitted).

            Taken together, the surety and going
        armed laws confirm what common sense
        suggests: When an individual poses a clear
        threat of physical violence to another, the
        threatening individual may be disarmed.
        Section 922(g)(8) is by no means identical to
        these founding era regimes, but it does not
        need to be. See Bruen, 

. Its
        prohibition on the possession of firearms by
        those found by a court to present a threat to
        others fits neatly within the tradition the
        surety and going armed laws represent.

Id. at 698.
                      DUNCAN V. BONTA                      35


    Section 922(g)(8), the Court held, is “relevantly similar”
to the Founding-era regimes in both why and how the law
burdens the Second Amendment right. Id. (quoting Bruen,

). As to “why,” both the historical regimes
and the modern law “restrict[] gun use to mitigate
demonstrated threats of physical violence.” 

 As to
“how,” the historical and modern laws require a judicial
determination of whether a defendant “likely would threaten
or had threatened another with a weapon.” Id. at 699. Both
the surety laws and the modern law are temporary in
duration. Id. Finally, the going-armed laws provided for
imprisonment, so § 922(g)(8)’s lesser restriction of
disarmament is permissible. Id.
    In dissent, Justice Thomas pointed out that § 922(g)(8)
addressed a “societal problem—the risk of interpersonal
violence—‘that has persisted since the 18th century,’ yet
was addressed ‘through the materially different means’ of
surety laws.” Id. at 752–53 (Thomas, J., dissenting) (quoting
Bruen, 

) (brackets omitted). He explained that
the historical regulations were “materially different” from
§ 922(g)(8)’s complete ban on firearm possession arising out
of private conduct. Id. at 764–71.
    Justice Thomas wrote that surety laws had the same
“why,” but the “how” could not be more different. Id. at
764. Surety laws, he noted, had no effect whatsoever on the
right to bear arms, either when posting a bond or when
forfeiting that bond because of a breach of the peace: “After
providing sureties, a person kept possession of all his
firearms; could purchase additional firearms; and could
carry firearms in public and private. Even if he breached the
peace, the only penalty was that he and his sureties had to
pay a sum of money.” Id. “At base, it is difficult to imagine
how surety laws can be considered relevantly similar to a
36                     DUNCAN V. BONTA


complete ban on firearm ownership, possession, and use.”
Id. at 766.
    As for the going-armed laws, Justice Thomas noted that
they “had a dissimilar burden and justification.” Id. at 767.
Going-armed laws prohibited only distinctly public acts;
they “did not prohibit carrying firearms at home or even
public carry generally.” Id. at 769. And those laws
“prohibited only carrying certain weapons (‘dangerous and
unusual’) in a particular manner (‘terrifying the good people
of the land’ without a need for self-defense) and in particular
places (in public).” Id. at 770. Plus, those laws “were
criminal statutes that penalized past behavior, whereas
§ 922(g)(8) is triggered by a civil restraining order that seeks
to prevent future behavior.” Id.
     The majority responded to Justice Thomas’ critique by
stating that it reached the opposite conclusion “[f]or the
reasons we have set forth,” id. at 700 (majority opinion), and
reiterating simply that “a ‘historical twin’ is not required,”
id. at 701 (quoting Bruen, 

).
    Applying the methodology described in Bruen and
Rahimi, we first conclude that (a) the “more nuanced
approach” described in Bruen applies here. 

.
We next consider (b) the historical regulations provided by
Defendant. Considering “how” and “why” the modern and
historical regulations burden the right to armed self-defense,
we conclude that (c) California’s law fits within the Nation’s
tradition of regulating firearms.         Finally, we reject
(d) Plaintiffs’ ownership-statistics argument before
(e) concluding that California’s law is constitutional.
                          DUNCAN V. BONTA                            37


    a. The “More Nuanced Approach” Applies Here.
    In Bruen, the Supreme Court stated that “cases
implicating unprecedented societal concerns or dramatic
technological changes may require a more nuanced
approach.” 

. The parties dispute whether this
case implicates unprecedented concerns or dramatic
technological changes.
    As an initial matter, the precise status of Bruen’s “more
nuanced approach” statement is unclear following Rahimi.
Rahimi addressed a societal challenge—domestic
violence—that has persisted since the Founding. And
nothing in the record suggested a dramatic technological
change. 5 The dissent insisted that the case, like Heller and
Bruen, fell neatly into the straightforward category, because
“§ 922(g)(8) addresses a societal problem—the risk of
interpersonal violence—‘that has persisted since the 18th
century.’” Rahimi, 

 (Thomas, J., dissenting)
(quoting Bruen, 

). Yet the majority did not
address whether that case implicated unprecedented societal
concerns or dramatic technological changes.
    Notwithstanding the Supreme Court’s silence on this
topic in Rahimi, we will not disregard Bruen’s statement that
a more nuanced approach applies to cases involving modern
problems or dramatic technological changes. Those cases
warrant an even more flexible approach than the Court
applied in Rahimi. To conclude otherwise would be to

5
  The Founders likely could not have imagined the weaponry available
today, so in that sense every Second Amendment case involves dramatic
technological changes. But Bruen could not have meant that type of
change, because it held that Bruen itself, along with Heller, were cases
that did not implicate dramatic technological changes. Bruen, 

.
38                    DUNCAN V. BONTA


disregard entirely a statement by the Supreme Court. Even
assuming that Bruen’s statement was dictum, we do not
lightly decline to follow a clear statement by the Supreme
Court. See, e.g., Fernandez-Ruiz v. Gonzales, 

 (9th Cir. 2006) (en banc) (“[A]s a lower federal
court, we are advised to follow the Supreme Court’s
considered dicta.” (quoting Oyebanji v. Gonzales, 

, 264–65 (3d Cir. 2005))).
    We readily conclude that a more nuanced approach is
appropriate here. This case implicates both unprecedented
societal concerns and dramatic technological changes. See
Hanson, 120 F.4th at 240–42 (holding that the nuanced
approach applies to a challenge to a ban on large-capacity
magazines); Ocean State, 

 (same); Ass’n of
N.J. Rifle & Pistol Clubs, Inc. v. Platkin, No. CV 18-10507-
PGS-JBD, 

, at *22 (D.N.J. July 30, 2024)
(same), cross appeals filed, Nos. 24-2415, 24-2450 (3d Cir.
Aug. 6 & 9, 2024); Capen v. Campbell, 

,
89–90 (D. Mass. 2023) (same), appeal filed, No. 24-1061
(1st Cir. Jan. 17, 2024); Del. State Sportsmen’s Ass’n v. Del.
Dep’t of Safety & Homeland Sec. (“DSSA”), 

, 598 (D. Del. 2023) (same), aff’d on other grounds,

 (3d Cir. 2024); Hanson, 671 F. Supp. 3d at
17–20 (same); Herrera v. Raoul, 

, 675
(N.D. Ill. 2023) (same), aff’d sub nom. Bevis, 

;
Kotek, 682 F. Supp. 3d at 924–27 (same); Nat’l Ass’n for
Gun Rights v. Lamont, 

, 104–07 (D.
Conn. 2023) (same); cf. Bianchi, 111 F.4th at 463
(concluding that the “more nuanced approach” applies to a
challenge to a ban on assault weapons).
    Mass shootings are clearly a societal concern that arose
only in the 20th century. The first known mass shooting in
the United States resulting in ten or more deaths occurred in
                       DUNCAN V. BONTA                       39


1949. Ocean State, 

. In the three decades that
followed, two such shootings occurred. In 2009 alone, three
mass shootings claimed ten or more lives, and many more
such shootings occurred in the years that followed. See, e.g.,

 at 44 n.4 (“The record suggests that mass shootings have
become more frequent and more deadly.”). In other words,
not a single mass shooting occurred until the middle of the
20th century, and we now experience these events regularly.
See Kotek, 682 F. Supp. 3d at 897–99 (detailing the rise of
mass shootings and their increasing lethality, particularly
when a large-capacity magazine is used). These tragedies
naturally receive significant media attention, and they have
spawned legislative action and citizen initiatives. It is hard
to imagine a clearer example of an “unprecedented societal
concern[].” Bruen, 

; see Hanson, 120 F.4th at
241 (“There can be little doubt that mass shootings are an
unprecedented societal concern.”); Bianchi, 111 F.4th at 463
(“The ripples of fear reverberating throughout our nation in
the wake of the horrific mass shootings . . . stem from a crisis
unheard of and likely unimaginable at the founding.”).
    Large-capacity magazines, when attached to a semi-
automatic firearm, also represent a dramatic technological
change from the weapons at the Founding. Semi-automatic
firearms equipped with large-capacity magazines fire with
an accuracy, speed, and capacity that differ completely from
the accuracy, speed, and capacity of firearms from earlier
generations. Hanson, 120 F.4th at 242, 248–51; Ocean State,

. The single-shot, muzzle-loading firearms
common at the Founding required slow, manual reloading.
Repeating Henry and Winchester rifles, which became
popular in the decades following the Civil War, required a
shooter to pump a lever manually, a process that allowed
about one shot per three seconds—much slower than the
40                     DUNCAN V. BONTA


firing rate of a modern semi-automatic firearm. Hanson, 671
F. Supp. 3d at 18–19. Notably, California’s law exempts
magazines designed for lever-action rifles. 

(c). We have no difficulty in concluding that large-
capacity magazines designed for semi-automatic firearms
represent a “dramatic technological change[].” Bruen, 

; see also Bianchi, 111 F.4th at 464 (“These are not
our forebears’ arms.”).
    For all of those reasons, we hold that a more nuanced
approach applies here. At the same time, we emphasize that
the result in this case does not hinge on this categorization.
Because we reach the same result under Rahimi’s
straightforward approach, we apply that approach below.
But our conclusion is buttressed by the Supreme Court’s
reservation of a more flexible analogical approach for
“unprecedented societal concerns or dramatic technological
changes.” Bruen, 

.
     Inexplicably, the principal dissenting opinion claims that
we contrived a “more nuanced approach” ourselves, Dissent
by J. Bumatay at 112–13, when in fact all we have done is to
quote the Supreme Court’s opinion. See Bruen, 

 (“[C]ases implicating unprecedented societal concerns or
dramatic technological changes may require a more nuanced
approach.”). Nor is our understanding of Supreme Court
precedent an outlier. As just noted, we follow essentially
every circuit-court and district-court decision in holding that
a more nuanced approach applies in the circumstances. The
dissenting opinion also faults us for mentioning, but not
utilizing, that approach. Dissent by J. Bumatay at 116. But,
because the Court did not flesh out how the “more nuanced
approach” operates—for instance, whether more recent
analogies should be consulted—we have taken the most
                       DUNCAN V. BONTA                      41


conservative path in our analysis by declining to apply the
more nuanced approach.
   b. Three Historical Legal Regimes Are Relevant.
    Beginning before the Founding and continuing
throughout the Nation’s history, legislatures have enacted
laws to protect innocent persons from especially dangerous
uses of weapons once those perils have become clear. We
discern three distinct categories of laws relevant to our
analysis.
    The first category of laws regulated the storage of
gunpowder. Early in the Nation’s history, gunpowder was
necessary to shoot a firearm. Kotek, 682 F. Supp. 3d at 903.
But the storage of gunpowder increased the risk of
explosions or fires, which posed an obvious threat to
innocent persons. Id. To mitigate the danger to innocent
lives, several colonies and states enacted laws restricting the
storage of gunpowder. E.g., 1771-1772 Mass. Province
Laws 167, ch. 9; 

, ch. 1549; 1782-1783
Mass. Acts 119–20, ch. 46; 

, ch. 28;
1786 N.H. Laws 383–84; 1798–1813 R.I. Pub. Laws 85, § 2;

, § 3; 

, ch. 25, § 1; 

, ch. 61; 1832 Conn. Acts 391, ch. 25; 1836
Conn. Acts 105, ch. 1, § 20. The laws typically prohibited
certain methods of storing gunpowder or restricted the
amount of gunpowder that could be stored in one place. One
Massachusetts law banned taking a firearm loaded with
gunpowder into any house or building in Boston. 

, ch. 46. Cities and towns, too, enacted laws
requiring that gunpowder be stored in certain containers or
on the highest story of the home. Act of Apr. 13, 1784, ch.
28, 1784 N.Y. Laws p. 627; An Act for Erecting the Town
of Carlisle, in the County of Cumberland, into a Borough,
42                     DUNCAN V. BONTA


ch. XIV, § XLII, 1782 Pa. Laws p. 41; An Act for Erecting
the Town of Reading, in the County of Berks, into a
Borough, ch. LXXVI, § XLII, 1783 Pa. Laws p. 140. In
1803, for example, Boston required that all gunpowder be
stored in powder houses. 

, ch. 20. In
sum, legislatures in the Founding era sought to prevent a
specific, infrequent type of harm to innocent persons—fires
and explosions from the storage of gunpowder—by
significantly restricting how and where persons could store
gunpowder.
    The second set of laws concerns trap guns—the rigging
of a firearm to discharge when a person unwittingly trips a
string or wire. People typically set trap guns to defend their
businesses, homes, or possessions. When trap guns became
popular, some people applauded their use as a deterrent to
crime. But others lamented that trap guns inevitably harmed
or killed innocent persons.
    Legislatures responded by banning the use of firearms as
trap guns. In 1771, the legislature of the Colony of New
Jersey found that “a most dangerous Method of setting Guns
has too much prevailed in this Province” and criminalized
the setting of trap guns. 1763–1775 N.J. Laws 346, ch. 539,
§ 10. Other jurisdictions followed suit. Nine states banned
the setting of trap guns in the 18th and 19th centuries, and
nine more states enacted bans early in the 20th century. In
sum, the use of firearms as trap guns posed a threat, albeit an
infrequent threat, to innocent persons, and legislatures
responded by prohibiting what had proved to be an
especially dangerous use of firearms: the setting of trap
guns.
    The third, and most extensive, set of laws consists of
significant restrictions on weapons after their use by
                       DUNCAN V. BONTA                        43


criminals exposed an especially dangerous use of the
weapon. These laws date from long before the Founding and
continue to today.
     The Statute of Northampton prohibited the carrying of
lances, for example, because those weapons generally were
appropriate only to engage in lawful combat “or—as most
early violations of the Statute show—to breach the peace.”
Bruen, 

. In the New World, states and colonies
prohibited the concealed carry of some weapons in response
to criminals’ secretly carrying those weapons to achieve
illicit ends. For example, after a period of strife between
planters and the colony’s proprietors, the Colony of East
New Jersey prohibited the concealed carry of “pocket
pistol[s], skeins, stilladers, daggers or dirks, or other unusual
or unlawful weapons.” Grants, Concessions, and Original
Constitutions of the Province of New Jersey, 289–90 (1881).
Massachusetts enacted similar laws, both as a colony and as
an early state. See 

, ch. 17 § 1
(prohibiting the carry of “clubs and other weapons” in a
group of twelve or more persons); 

, ch.
38 (prohibiting being armed with a club or other weapon
while rioting); see also Bevis v. City of Naperville, 

, 1070 (N.D. Ill.) (describing similar
restrictions), aff’d, 

 (7th Cir. 2023).
    As new weapons gained popularity and notoriety for
their criminal use, legislatures imposed significant
restrictions on them. For example, in 1827, Jim Bowie used
a large, specially designed knife in a duel. “Bowie knives,”
as they came to be called, proliferated in the 1830s. The
knives had design features that were particularly suitable for
fighting: long blades, crossguards to protect the wielder’s
hands, and points designed to make it easier to harm a
victim. Criminals used them widely in fights and duels.
44                       DUNCAN V. BONTA


States acted quickly. By 1840, at least five States or
territories had enacted laws restricting the carrying of Bowie
knives or other fighting knives. By the end of the 19th
century, nearly every State had enacted laws restricting
Bowie knives, including by outlawing their concealed or
unconcealed carry and sale, by enhancing criminal penalties
for their use, or by taxing their ownership.
    The “slungshot” followed a similar trajectory. A
slungshot is a hand-held impact weapon with a weighted
object at the end of a flexible strap. Invented in the 1840s,
its use by criminals and street gangs became widespread.
States again reacted. In 1849, New York and Vermont
prohibited the manufacture, sale, or carry of slungshots,
punishable by up to five years’ imprisonment. 

, §§ 1-2, ch. 278; 

,
No. 36 §§ 1-2. By the end of the century, nearly every State
had enacted anti-slungshot laws.
    States also responded to advances in firearm technology.
In the first half of the 19th century, percussion-cap pistols
and revolvers allowed pistols to remain loaded for longer
and to contain up to six bullets. Criminals used such pistols
with increasing frequency to resolve interpersonal disputes.
Several states responded by restricting the carry of
concealable pistols. E.g., 

, An Act
to Preserve the Peace and to Prevent Homicide, ch. 90, § 1;

, An Act to Preserve the Public Peace and
Prevent Crime, chap. XCVI, § 1-2.
   A clear pattern emerges from a review of this third set of
regulations. 6    When criminals took advantage of

6
 Although we choose to stop our survey of historical laws in the 19th
century, we note that, as technological advances continued to increase
                          DUNCAN V. BONTA                            45


technological advances in weapons, legislatures acted to
restrict an especially dangerous use of those weapons:
Bowie knives were designed to—and did—cause significant
harm in fights, with little self-defense value, so legislatures
banned their carry outside the home; the slungshot proved
incredibly useful to criminals but of minimal value in self-
defense, so legislatures banned their carry outside the home;
and pistols became easy for criminals to conceal, to the
detriment of public safety, so legislatures banned their
concealed carry. Legislatures sought to prevent a specific
type of harm to innocent persons—criminal use of new
technology—by prohibiting what had proved to be
especially dangerous uses of the new weapons, primarily the
ability to carry an extremely deadly weapon concealed from
law enforcement and bystanders.
    c. California’s Ban on Large-Capacity Magazines Falls
       Within the Nation’s Tradition of Firearm Regulation.
     We discern two distinct traditions from the legal regimes
described above. First, the Founding-era gunpowder-
storage regulations established an early tradition of laws
seeking to protect innocent persons from infrequent but
devastating harm by regulating a component necessary to the
firing of a firearm. Second, since the Founding era,
legislatures have enacted laws to protect innocent persons
from especially dangerous uses of weapons once those perils
have become clear. See Hanson, 120 F.4th at 237–38

the lethality of firearms, legislatures throughout the Nation acted to
restrict significantly a range of weapons, including sawed-off shotguns,
“Tommy guns,” semiautomatic weapons, and automatic weapons. See,
e.g., Hanson, 120 F.4th at 239 (describing some of these weapons and
the resulting federal regulations); Kotek, 682 F. Supp. 3d at 909–11
(describing many of the weapons and resulting regulations by state
legislatures and by Congress).
46                         DUNCAN V. BONTA


(recognizing the tradition of regulating “weapons that are
particularly capable of unprecedented lethality”); Ocean
State, 

 (recognizing the tradition of regulating
dangerous aspects of weapons “once their popularity in the
hands of murderers became apparent”); Bevis, 

 (describing “the long-standing tradition of regulating
the especially dangerous weapons of the time”); see also
Bianchi, 111 F.4th at 464–72 (extensively discussing “a
strong tradition of regulating those weapons that were
invented for offensive purposes and were ultimately proven
to pose exceptional dangers to innocent civilians”). 7
Whether we view those traditions independently or together,
California’s ban on large-capacity magazines falls well
within them. As described below, the ban is “‘relevantly
similar’” to the historical laws in both “why and how it
burdens the Second Amendment right.” 8 Rahimi, 

 The district court in Kotek reached the same conclusion after reviewing
essentially the same regulations that we consider:
         Throughout this Nation’s history, new technologies
         have led to the creation of particularly dangerous
         weapons. As those weapons became more common,
         they became tied with violence and criminality. In
         response, governments passed laws that sought to
         address the features of those weapons that made them
         particularly dangerous to public safety.
682 F. Supp. 3d at 935; see also Lamont, 685 F. Supp. 3d at 71 (reaching
the same conclusion because, “when a modern innovation in firearm
technology results in a particular type of weapon or method of carrying
being utilized for unlawful purposes to terrorize and endanger the public,
the Nation has a longstanding history and tradition of regulating those
aspects of the weapons or manners of carry that correlate with rising
firearm violence”).
8
 Our analysis below dutifully compares the “why” for the modern law
with the “why” for the historical laws and compares the “how” for the
                          DUNCAN V. BONTA                             47


at 698 (quoting Bruen, 

). California’s law thus
“is consistent with the principles that underpin our
regulatory tradition.” Id. at 692.
    We first examine the tradition set by the gunpowder-
storage laws. Both those early laws and California’s modern
law share the same justification for burdening the right to
armed self-defense: to protect innocent persons from
infrequent but devastating harm caused or exacerbated by a
component necessary to the firing of a firearm. Gunpowder
caused fires and explosions only infrequently, but
legislatures nevertheless recognized that those infrequent
events could cause devastating harm. The legislatures
therefore imposed significant restrictions on how and where
gunpowder could be stored, even though gunpowder was a
necessary component to the firing of a firearm.
    The same justification underpins California’s restriction
on magazine capacity: to protect innocent persons from
infrequent but devastating harm. Mass shootings (at least as
defined by shootings resulting in more than ten deaths) are,
thankfully, not everyday occurrences. But there is no
dispute that mass shootings, when they occur, cause
devastating harm. Mass shootings are devastating for the
entire community, and large-capacity magazines exacerbate
the harm. The short pauses when a shooter must reload a
firearm afford intended victims and law enforcement
officers a precious opportunity to flee, take cover, and fight
back. Ocean State, 

; ANJRPC, 910 F.3d at


modern law with the “how” for the historical laws. To the extent that the
principal dissent reaches a different conclusion from that analysis, we
respectfully disagree. But we are baffled by the dissent’s further
suggestion that we somehow “compare the ‘how’ to the ‘why.’” Dissent
by J. Bumatay at 119.
48                    DUNCAN V. BONTA


119–20 & n.24; Kolbe, 

; Kotek, 682 F. Supp.
3d at 898–99; Platkin, 

, at *25. Large-
capacity magazines exacerbate the harm caused by mass
shootings, and limiting magazine capacity thus prevents or
mitigates the harm caused by mass shootings. In sum, both
the Founding-era legislatures and California’s legislature
and voters enacted measures that burdened the Second
Amendment right in order to prevent or mitigate a known,
albeit infrequent, cause of devastating harm. See Ocean
State, 

 (discussing the relevance of gunpowder-
storage laws).
    The gunpowder-storage laws and California’s law are
also “relevantly similar” in how they burden the right to
armed self-defense. Rahimi, 

 (quoting
Bruen, 

). Both the historical laws and
California’s law target the component that causes or
exacerbates the devastating harm, and both affect the speed
at which a person can fire a firearm. Founding-era
legislatures regulated the storage of gunpowder because that
component caused or exacerbated fires and explosions.
Similarly, California’s legislature and voters regulated the
capacity of magazines because, as discussed above, that
component causes or exacerbates mass shootings. Both laws
also impose a size restriction commensurate with the threat
to public safety. Some gunpowder-storage laws imposed a
limit on the quantity of gunpowder that could be stored in
order to limit the harm caused by a fire or explosion; and
California’s law limits the quantity of bullets that may be
placed in a magazine in order to limit the harm caused by a
mass shooting.
    Perhaps most pertinently to the analysis here, the laws
also plainly affect the speed at which a person could fire a
firearm. Laws requiring that gunpowder be stored on the
                       DUNCAN V. BONTA                      49


highest floor of a home, for example, clearly delayed the
ability of a resident to respond with a firearm to a ground-
floor intruder or to an incident in the street or yard. Towns
prohibiting altogether the storage of gunpowder had a much
greater effect on the ability of a person to use a firearm with
speed; a person wishing to fire a firearm had to retrieve
gunpowder from a powder house or a location outside of
town. California’s law, too, affects a person’s ability to
respond with speed. California’s law permits a person to fire
ten rounds without pause but, before firing the eleventh
round, the shooter must pause to reload the magazine, use a
second magazine, or use a second firearm. Viewed through
this lens, California’s law has a significantly smaller effect
on the speed of armed self-defense. Gunpowder-storage
laws could impose delays of minutes before a person could
fire a single shot, whereas California’s law imposes a delay
of only seconds and only after a person has fired up to ten
rounds.
    In conclusion, California’s law falls within the national
historical tradition of regulating a component necessary to
the firing of a firearm in order to prevent or mitigate
devastating harm caused or exacerbated by that component.
See Ocean State, 

 (“It requires no fancy to
conclude that those same founding-era communities [that
enacted gunpowder-storage laws] may well have responded
to today’s unprecedented concern about [large-capacity
magazine] use just as the Rhode Island General Assembly
did: by limiting the number of bullets that could be held in
a single magazine.”).
    We next turn to the national historical tradition of laws
represented by trap-gun bans and restrictions on Bowie
knives, slungshots, and concealable pistols. Legislatures
throughout our Nation’s history have banned especially
50                         DUNCAN V. BONTA


dangerous uses of weapons once the threat to innocent
persons has become clear. 9 Both the historical laws and
California’s law share the same justification: to protect
innocent persons from harm from especially dangerous uses
of weapons. Legislatures recognized the threat from the use
of a firearm as a trap gun by banning that particular,
especially dangerous use.           Similarly, as criminals
increasingly used specific weapons by carrying them outside
the home or by concealing them, legislatures banned those
particular, especially dangerous uses of the weapons.
California’s law, too, reflects the growing threat to public
safety from the use of large-capacity magazines. As
described above, large-capacity magazines cause or
exacerbate the harm from mass shootings, and limiting
magazine capacity prevents or mitigates the harm from those
events because a shooter must pause before firing an
eleventh round.      California’s law bans a particular,
especially dangerous use of firearms—the use of a large-
capacity magazine—in order to protect public health. See,
e.g., Hanson, 120 F.4th at 240 (concluding that the historical
laws and a ban on large-capacity magazines “share the same
basic purpose: To inhibit then unprecedentedly lethal
criminal activity by restricting or banning weapons that are
particularly susceptible to, and were widely used for,
multiple homicides and mass injuries”); DSSA, 664 F. Supp.
3d at 603 (concluding that historical regulations were


9
  The principal dissent repeatedly mischaracterizes the relevant tradition
as a ban on “especially dangerous weapons.” Dissent by J. Bumatay at
79, 98–99, 118, 119 (several times), 120 (twice). As we emphasize
repeatedly, the relevant tradition identified here is a tradition of banning
especially dangerous uses of weapons once the perils of those uses
becomes clear. By mischaracterizing the relevant tradition, the principal
dissent spends much effort attacking a nonexistent assertion.
                           DUNCAN V. BONTA                               51


relevantly similar as to the “why” because those regulations,
and a ban on large-capacity magazines, “were enacted in
response to pressing public safety concerns regarding
weapons determined to be dangerous”).
    We next examine “how” the regulations burden the
Second Amendment right, by considering whether
California’s law and the historical regulations “impose a
comparable burden on the right of armed self-defense.”
Bruen, 

. With respect to armed self-defense,
the only effect of California’s ban on large-capacity
magazines is that a person may fire a semi-automatic
weapon no more than ten times without a short pause to
change magazines (or reload the original magazine or fire a
different weapon). In other words, the law prohibits only
one very specific use of some firearms: the shooting of an
eleventh (or successive) round without a brief pause. 10 The
law imposes no limit whatsoever on the number of
magazines a person may own, the number of bullets a person
may own, or the number of firearms a person may own. The
law also imposes no limit on the number of rounds a person
may fire or the number of firearms a person may fire. Nor,
despite Plaintiffs’ protestations to the contrary, does the law
ban any weapon. A person wishing to buy any lawful


10
   Like other courts, we reject the suggestion that a person “uses” a large-
capacity magazine even when not firing the weapon. Ocean State, 

 n.8; Hanson, 671 F. Supp. 3d at 15. Whereas brandishing a
firearm can have a deterrent effect on would-be attackers, there is no
evidence in the record that others can tell that a magazine attached to an
unfired weapon is large-capacity or that such magazines would provide
any additional deterrent effect. See Ocean State, 

 n.8
(“[The] plaintiffs claim no plausible scenario in which a threat has
proved less effective because the brandished weapon could only fire ten
rounds at once without reloading.”).
52                         DUNCAN V. BONTA


firearm (or other weapon) is free to do so. The owner may
possess that firearm at home for self-defense and, so far as
this law is concerned, may carry it in any manner, and to any
place, that state law allows.
    The burden imposed by California’s law is comparable
to the burden imposed by the historical laws. Each of those
laws, like California’s law, burdened the right to armed self-
defense by prohibiting a specific, particularly dangerous use
of a weapon. Like California’s law, the trap-gun laws
allowed persons to use firearms in every way except one way
that proved, at the relevant time, particularly dangerous to
innocent persons: the rigging of trap guns. Similarly,
various laws throughout the Nation’s history regulated the
right to armed self-defense by prohibiting specific uses of
weapons that had proved particularly dangerous: we have
noted the examples of concealed carry, carry more generally,
carry of weapons in a group of twelve or more persons, and
carry of a weapon while rioting. Those laws, too, prohibited
the use of weapons in ways that had proved, in their time,
especially dangerous. Legislatures throughout the Nation’s
history thus have chosen, as California’s legislature and
voters have chosen, to impose a confined regulation of
armed self-defense by prohibiting a specific, especially
dangerous use of a weapon. 11

11
   When considering “how” the legislature has burdened the right to
armed self-defense, we understand the Supreme Court’s focus to be
about the method of burdening the right, rather than the magnitude of the
burden. We therefore describe in text how California’s law and the
historical laws burden the right by prohibiting a specific, particularly
dangerous use of a weapon. To the extent that the magnitude of the
burden is relevant, California’s law imposes only a minimal burden on
the right of armed self-defense. Firing more than ten rounds occurs only
rarely, if ever, in armed self-defense. The evidence in this record, and in
                          DUNCAN V. BONTA                             53


    Plaintiffs’ primary argument to the contrary is that
California’s law imposes a materially different burden on
armed self-defense than the historical laws because, unlike
those laws, California’s law prohibits the possession of
large-capacity magazines. We disagree both with Plaintiffs’
reasoning and with their premise.
    Most fundamentally, the burden imposed by the modern
law need not be an exact match to the burden imposed by
historical laws. California’s law “is by no means identical
to” the relevant historical laws, “but it does not need to be.”
Rahimi, 

. Its prohibition on a weapon’s
component that serves the sole function of enabling a
specific, and especially dangerous, use of a firearm fits


other cases, demonstrates that a person seldom shoots more than ten
rounds when defending with a firearm. Hanson, 120 F.4th at 245; Ocean
State, 

; Worman v. Healey, 

 (1st Cir. 2019),
abrogated in other part by Bruen, 

; Kolbe, 

;
Capen, 708 F. Supp. 3d at 91; Kotek, 682 F. Supp. 3d at 896–97. And
even in those extremely rare instances, the record does not disclose
whether the shooter fired more than ten bullets in rapid succession,
without a short pause that would have allowed reloading or switching
weapons. In sum, California’s law places a limited burden on the Second
Amendment’s right to armed self-defense by prohibiting only one
specific and rare use of semi-automatic firearms that accept detachable
magazines—the firing of more than ten rounds without a short pause
after the tenth round.
  The magnitude of that burden is relevantly similar to the magnitude of
the burden of the historical laws. The trap-gun laws undoubtedly
burdened the right to armed self-defense in specific situations. A person
worried about a nighttime intruder had to remain awake and alert and
could not rely on a trap gun. And the historical restrictions on carrying
weapons imposed an even greater burden: A person skilled at using a
concealable pistol, Bowie knife, or slungshot could not depend on those
weapons when leaving home.
54                     DUNCAN V. BONTA


neatly within the tradition that the historical regulations
represent.
    Rahimi is instructive. Section 922(g)(8) prohibits
persons subject to a domestic-violence restraining order
from possessing any firearm. Id. at 688–89. The surety
laws, as Justice Thomas pointed out, imposed no burden
whatsoever on armed self-defense; they required merely
posting a bond and, in the case of a breach, forfeiting the
bond. Id. at 764–67 (Thomas, J., dissenting). Similarly, the
going-armed laws burdened armed self-defense only after a
jury trial, with all its attendant protections for the accused,
and only for public breaches of the peace, whereas the
modern law burdened armed self-defense with few
procedural protections and for the altogether different
conduct of a private threat. Id. at 768–71. The Rahimi
majority rejected those differences as insignificant,
explaining that, “[a]s we said in Bruen, a ‘historical twin’ is
not required.” Id. at 701 (quoting Bruen, 

).
     California’s law fits comfortably into historical tradition.
Even accepting Plaintiffs’ premise—which we do not, for
the reasons described below—that the burden imposed by
California’s law is different in some way than the burdens
imposed by the historical laws, a historical twin is not
required.     Like the historical laws, California’s law
functionally prohibits a particular, especially dangerous use
of a weapon. That law is “relevantly similar” to the
historical laws. 

 at 698 (quoting Bruen, 

).
Moreover, the regulation of a component necessary to the
firing of a firearm is far from unprecedented. As described
above, the Founding generation, through gunpowder-storage
laws, imposed significant restrictions on a component
absolutely necessary at the time to the firing of a firearm.
                       DUNCAN V. BONTA                       55


     To the extent that California’s law differs
meaningfully—again, a premise that we reject—any
difference is precisely because of the factors that Bruen
mentioned. 

. The voters of California
determined that modern experience had shown that laws
short of bans on possession had been ineffective and nearly
impossible to enforce, and mass shootings are a uniquely
modern phenomenon resulting from dramatic improvements
in technology. Prop. 63 §§ 2(12), 3(8). It is inconsistent
with the Supreme Court’s instructions to reason that,
because a ban on the carry of Bowie knives, for example,
may have proved sufficient to mitigate criminal use of
Bowie knives, legislatures and citizen initiatives are limited
to precisely the same restrictions when addressing new
technology that enables a new, more devastating type of
societal harm. To the contrary, the Supreme Court has
cautioned us that its “precedents were not meant to suggest
a law trapped in amber.” Rahimi, 

; see also

 at 739–40 (Barrett, J., concurring) (“[I]mposing a test that
demands overly specific analogues has serious problems. To
name two: It forces 21st-century regulations to follow late-
18th-century policy choices, giving us ‘a law trapped in
amber.’ And it assumes that Founding-era legislatures
maximally exercised their power to regulate, thereby
adopting a ‘use it or lose it’ view of legislative authority.
Such assumptions are flawed, and originalism does not
require them.” (citation omitted)).
     Moreover, Plaintiffs’ premise is mistaken; California’s
law bans no weapon. We reiterate that a large-capacity
magazine is not itself a weapon. It is an accessory whose
sole function is to provide some firearms with the ability to
fire more than ten rounds without a short pause. In this way,
California’s law imposes less of a burden than the historical
56                    DUNCAN V. BONTA


laws, which regulated weapons themselves. A person may
carry a firearm freely, but Bowie knives and slungshots must
be left at home.
     In sum, as other courts have concluded with respect to
similar bans on large-capacity magazines, we conclude that
California’s law is “relevantly similar” to historical
regulations in “how” it burdens the right to armed self-
defense. Rahimi, 

; Hanson, 120 F.4th at 237–
38 (discussing historical regulations of the Bowie knife);
Ocean State, 

 (same); Bevis, 

(same); Platkin, 

, at *20, *24 (same);
DSSA, 664 F. Supp. 3d at 600–01 (describing historical
regulations of the Bowie knife, slungshot, and revolver
pistol); Kotek, 682 F. Supp. 3d at 903–10, 928–33
(describing many of the same historical regulations we
discuss and explaining why the burden they imposed was
relevantly similar to the burden imposed by Oregon’s ban on
large-capacity magazines); Bevis, 657 F. Supp. 3d at 1068–
71 (describing historical regulations of the Bowie knife,
slungshot, and trap gun); see also Bianchi, 111 F.4th at 464–
68 (describing historical regulations of gunpowder, the
Bowie knife, dirk, sword cane, metal knuckles, slungshot,
and sand club and concluding that a ban on assault weapons
is relevantly similar to those historical regulations).
    In conclusion, California’s law is relevantly similar to
the historical laws in both why and how it burdens the right
to armed self-defense, and it falls within the national
historical tradition of regulating a particular, especially
dangerous use of a weapon, once that use becomes a specific
threat to innocent persons.
                       DUNCAN V. BONTA                       57


   d. We   Reject         Plaintiffs’    Ownership-Statistics
      Argument.
    In Heller, the Supreme Court overturned a District of
Columbia ban on all handguns because it “amounts to a
prohibition of an entire class of ‘arms’ that is
overwhelmingly chosen by American society for th[e]
lawful purpose” of self-defense. 

. Plaintiffs
argue that California’s law falls into the same category
because it, too, is “a prohibition of an entire class of ‘arms’
that is overwhelmingly chosen by American society for that
lawful purpose.” 

 After all, Plaintiffs point out, many
firearm owners own large-capacity magazines. According
to Plaintiffs, “that should be the end of the analysis.” We
reject that simplistic approach.
    For the reasons described in Part A, above, large-
capacity magazines are not “arms.” Even assuming the
contrary, large-capacity magazines remain optional, and
they remain an accessory to some firearms. Accepting
Plaintiffs’ argument would require concluding that the
Second Amendment never permits a legislature to ban any
optional accessory to any weapon, provided that enough
people purchased enough of them before a legislature could
act. We do not read the Supreme Court’s precedents in that
rigid manner. Instead, we take at face value the instruction
that a modern law “must comport with the principles
underlying the Second Amendment, but it need not be a
‘dead ringer’ or a ‘historical twin.’” Rahimi, 

(quoting Bruen, 

).
    Consider, for example, machine guns. Federal law
prohibits their possession except in very limited
circumstances. 

(o). The Supreme Court
stated in Heller that it would be “startling” to read the Second
58                         DUNCAN V. BONTA


Amendment as prohibiting a ban on machine guns, and the
Court clearly signaled that one machine gun—the M-16—
could be banned. 

. It is estimated that
civilians own more than 176,000 machine guns (and nearly
one million machine guns exist in the country, when one
counts those owned by law enforcement officers). DSSA,
664 F. Supp. 3d at 592. Plaintiffs do not explain why, under
their ownership-statistics theory, 176,000 is insufficient
while the somewhat larger, but unknown, number of large-
capacity magazines suffices. 12
    Moreover, if Congress chose to let the ban on machine
guns expire, as Congress did with respect to large-capacity
magazines, and if civilians purchased more machine guns,
would a state-law ban on machine guns suddenly change
from constitutional to unconstitutional? How many more
would civilians have to buy before that binary change took
effect? We do not read the Constitution or the Supreme
Court’s precedents to hinge on the necessarily speculative
answers to those questions. Instead, we must ask whether
Plaintiffs’ proposed conduct falls within the text of the

12
   In addition to the uncertainty about the total number of large-capacity
magazines owned by civilians, we also do not know how many were
truly “chosen by American society for th[e] lawful purpose [of self-
defense].” Heller, 

. Among other questions, we do not
know how many purchases were made simply because the large-capacity
magazine comes as standard equipment with the purchase of a firearm.
See, e.g., Duncan V, 19 F.4th at 1126–27 (Berzon, J., concurring) (“[A]
device may become popular because of marketing decisions made by
manufacturers that limit the available choices. Here, for example, large-
capacity magazines come as a standard part on many models of firearms,
so a consumer who wants to buy those models has no choice regarding
whether the weapon will include a magazine that can fire more than ten
rounds without reloading.”). Moreover, there is no constitutional right
to factory settings.
                       DUNCAN V. BONTA                       59


Second Amendment and, if so, whether the law “is
consistent with the principles that underpin our regulatory
tradition.” Rahimi, 

 (citing Bruen, 597 U.S.
at 26–31).
    Heller addressed a true ban on a class of common
firearms, including all uses of those weapons, and must be
understood in that light. California’s law, by contrast, bans
only one type of optional accessory to some firearms—
functionally prohibiting only one specific use that is rarely,
if ever, used in self-defense. The Supreme Court’s recent
decisions in Bruen and Rahimi have described at length the
approach that we must apply when assessing the
constitutionality of modern firearm regulations. We reject
Plaintiffs’ facile invitation to jettison that approach and hold
that, any time an undefined number of people own an
undefined number of any optional accessory to any weapon,
no legislature may ban that accessory, no matter how rarely
that accessory is used in armed self-defense. See Hanson,
120 F.4th at 233–34 (explaining why a simplistic ownership-
statistics argument conflicts with Bruen); Ocean State, 95
F.4th at 50–51 (detailing at length many flaws in the same
ownership-statistics argument); Bevis, 

(discussing a flaw in the argument); DSSA, 664 F. Supp. 3d
at 592–93 (rejecting the same ownership-statistics
argument); see also Bianchi, 111 F.4th at 459–61 (discussing
similar flaws in the same ownership-statistics argument for
assault weapons).
   e. California’s Law Fits the Nation’s Tradition.
    In sum, even assuming that Plaintiffs’ proposed conduct
of possessing large-capacity magazines implicates the plain
text of the Second Amendment, California’s law fits within
the Nation’s tradition of regulating weapons. Accordingly,
60                    DUNCAN V. BONTA


Plaintiffs’ Second Amendment challenge fails for this
second, alternative reason.
    REVERSED AND REMANDED with the instruction
to enter judgment in favor of Defendant.


BERZON, Circuit Judge, with whom MURGUIA, Chief
Judge, and HURWITZ, PAEZ, SR THOMAS, and
WARDLAW, Circuit Judges, join, concurring:

    I concur in full in the majority opinion. Here, I address
Judge VanDyke’s novel form of “dissent.” Judge
VanDyke’s dissent improperly relies on factual material that
is unquestionably outside of the record. See Majority Op. at
13–14 n.1. His source for these beyond-the record facts? A
video that he recorded, in his own chambers, showing him
handling several different handguns and explaining his
understanding of their mechanics and operation.
    I write separately to point out two fundamental problems
with Judge VanDyke’s reliance on his self-made video:
First, the video is not part of his written dissent and it
includes facts outside the record, so the panel is right to
ignore it. Second, and more egregiously, Judge VanDyke has
in essence appointed himself as an expert witness in this
case, providing a factual presentation with the express aim
of convincing the readers of his view of the facts without
complying with any of the procedural safeguards that usually
apply to experts and their testimony, while simultaneously
serving on the panel deciding the case. While the facts Judge
VanDyke asserts must be ignored, his wildly improper video
presentation warrants additional comment, lest the genre
proliferate.
                          DUNCAN V. BONTA                             61


                                   I.
    Judge VanDyke’s video is, in his words, a “visual
illustration” meant to “aid [his] colleagues and the parties.”
Dissent at 125. The “amateur” majority, he writes, bases its
analysis on “a nonexistent reality.” Dissent at 128, 146. So
Judge VanDyke (who, he suggests, does understand these
matters) purports to “show[] that this reality doesn’t exist”
by explaining “how guns are made, sold, used, and
commonly modified”—all facts, despite Judge VanDyke’s
protestations to the contrary. Dissent at 146; Lawrence
VanDyke, Video, at 5:09-13 (March 20, 2025),
https://www.ca9.uscourts.gov/media/23-55805/opinion.
      Judge VanDyke asserts that the video, to which his
opinion includes a link, is “part” of his dissent, “deliver[ed]
. . . orally—via video” rather than in writing. Dissent at 125.
But the video is not “part” of his dissent simply because
Judge VanDyke says it is. To the contrary, our circuit’s
general orders require that “the determination of each appeal
. . . shall be evidenced by a written disposition.” 9th Cir. Gen.
Order 4.5a (emphasis added). 1 Our rules do not allow a video
to operate as a “disposition,” a term that includes separate
opinions. 2


1
  Rules and statutes similarly require that decisions by federal district
judges be memorialized in writing. For example, the Federal Rules of
Civil Procedure contemplate oral decisions when district judges rule on
motions or make findings and conclusions in bench trials, but the rules
require that any decisions not evidenced by a written opinion or
memorandum “be stated on the record” in open court. See Fed. R. Civ.
P. 52(a)(1), (a)(3). And by statute, all district court sessions must “be
recorded verbatim” to enable transcription. 

(b).
2
  General Order 4.5a refers to the “disposition” and the “majority
disposition” as shorthand for “written disposition,” including when it
62                        DUNCAN V. BONTA


    Of course, in bygone days, before computers,
typewriters, cameras, or microphones, judges delivered
decisions orally from the bench. Erwin C. Surrency, Law
Reports in the United States, 

, 55
(1981). But it’s not the 1750s anymore. We have long since
moved past an “unwritten” system “retained . . . by memory
and custom.” 1 William Blackstone, Commentaries *63
(1765). States began requiring courts to reduce opinions to
writing as early as 1784. See, e.g., Acts and Laws of the State
of Connecticut in America 267–68 (1784) (Act of May 2,
1784). In this circuit, written decisions have been part of our
practice since our founding in 1891. See, e.g., United States
v. Sutton, 

 (9th Cir. 1891).
    So today, we ground our jurisprudence in written
precedent. See Peter Tiersma, The Textualization of
Precedent, 

 (2013). And we do
so for good reason: Written opinions promote uniformity,
predictability, accountability, and care. “[W]riting seems to
have the advantage of inducing greater care,” as the Scottish
judge Henry Cockburn noted; “Men don’t boggle at
speaking nonsense which they would hesitate to put
permanently down upon paper.” 2 Journal of Henry
Cockburn 154 (Edinburgh, Edmonston & Douglas 1874).
    True, times have changed: New technologies might
today make it easier to preserve and distribute oral opinions
than in centuries past. But even in an age of online videos,
written opinions are more clear, useful, and accessible, and



refers to “[a]ny separate concurring or dissenting disposition.” The
General Order thus treats the term “disposition” as referring exclusively
to written dispositions.
                          DUNCAN V. BONTA                            63


there are many potential challenges with video dispositions. 3
In any event, our entire legal system has long since evolved
to one built around written precedent. And in this circuit, our
rules require it. Perhaps our written-disposition rule should
be reevaluated in light of new technology. But we have a
clearly defined process for considering such changes; that
process has yet to be invoked toward that end.
    Judge VanDyke’s video is not, then, technically
speaking, “part” of his dissent. So what is it? It is not a video
that is itself part of the record. Cf., e.g., Norse v. City of Santa
Cruz, 

 (9th Cir. 2010) (Kozinski, J.,
concurring). It is not a recording of an oral argument or some
other court proceeding. 4 Cf., e.g., Cadena v. Customer
Connexx LLC, 

, 914–15 n.11 (9th Cir. 2024).
And it is not a link to a video offered as a citation in support
of the judicially noticeable fact that the video exists and is
available on the internet. Cf., e.g., Brown v. Ent. Merchs.
Ass’n, 

 (2011) (Breyer, J., dissenting).
Each of these reasons for linking to a video is well-
established and permissible. But Judge VanDyke links to his
video for a different purpose—to provide facts not in the
record, by demonstration. The video itself is not part of the



3
  For example, where would videos be hosted for later access? How
could their contents be searched and cross-referenced? Would courts and
reporters be able to ensure that the recordings remain available
indefinitely? Would pro se litigants and prisoners have access to the
videos online? Would all the videos be transcribed? If so, how would
transcripts capture non-verbal signals like tone and facial expressions,
let alone visual demonstrations like Judge VanDyke’s?
4
 Judge VanDyke’s video contains a short excerpt from the oral argument
in this case. I do not take issue with that portion of his recording.
64                       DUNCAN V. BONTA


record, and the facts asserted therein are not subject to
judicial notice.
    “Save in unusual circumstances, we consider only the
district court record on appeal.” Lowry v. Barnhart, 

 (9th Cir. 2003); see also Fed. R. App. P. 10.
There are a few narrow exceptions—for example, to correct
inadvertent omissions, to take judicial notice when
appropriate, or if new factual developments have rendered a
case moot. Lowry, 

. I would have thought
the proposition obvious, but it apparently bears emphasis
that a judge wanting to provide an unrequested “visual
illustration” to help his “colleagues and the parties”
understand the case, Dissent at 125, is not one of these
established exceptions. Not even close. 5
    The majority opinion thus considers the video no
differently than it would any other factual source that is not
in the record and not subject to judicial notice or another of
the narrow exceptions: it ignores it.
                                II.
    But there is another, even more troublesome problem
with the recording: Judge VanDyke himself appears in the
recorded presentation making factual assertions about how
guns work and providing physical demonstrations to support
his assertions. By doing so, Judge VanDyke casts himself in
the role of an expert witness, speaking to the type of
“technical” and “specialized” issues that are reserved for
witnesses properly “qualified as an expert.” See Fed. R.
Evid. 701, 702. He catalogues according to his own criteria

5
  If an attorney (rather than a judge) submits and relies on material
outside the record, we have held the conduct sanctionable. See Lowry,
329 F.3d at 1025–26.
                       DUNCAN V. BONTA                       65


various handgun components, describes their functions, and
provides a physical demonstration about how they are
attached to a firearm and replaced. He opines on the relative
merits of different types of takedown levers, lighter versus
heavier grips, and iron sights versus red dot optics. He
repeatedly avers that certain features make “the gun more
dangerous when it’s misused, but also make[] the gun more
effective for its intended purpose.” Lawrence VanDyke,
Video, at 11:11-11:31; 10:01-10:16; 13:07-13:21 (March 20,
2025),              https://www.ca9.uscourts.gov/media/23-
55805/opinion. And he speaks to his understanding as to
whether certain components are factory standard or
frequently used.
    All these topics are commonly the province of expert
testimony. See, e.g., United States v. Spinner, 

 (D.C. Cir. 1998) (expert testimony about technical
features of an AR-15 including its grip); United States v.
Meadows, 

, 853–54 (7th Cir. 1996) (expert
testimony about the components and characteristics of a gun
that was converted into a rifle); Oregon Firearms Fed’n v.
Kotek, 

, 912, 922 (D. Or. 2023) (expert
testimony about the mechanics of magazines and the relative
merits of high-capacity magazines); Nat’l Ass’n for Gun Rts.
v. Lamont, 

, 72–75 (D. Conn. 2023)
(expert declaration about the mechanics of automatic and
semiautomatic firearms); United States v. Hasson, No. 19-
96, 

, at *2 (D. Md. Sept. 20, 2019) (expert
testimony about the features of silencers and their interaction
with firearms); Barnett v. Raoul, No. 23-CV-00141, 

, at *36 (S.D. Ill. Nov. 8, 2024) (expert
testimony about the merits of features like “the ability to fire
semiautomatically, detachable magazines, pistol grips,
forward-protruding grips, thumbhole stocks, adjustable
66                     DUNCAN V. BONTA


stocks, flash suppressors, barrel shrouds, buffer
tubes/braces, and threaded barrels” in facilitating self-
defense).
    Myriad rules govern the submission and presentation of
expert testimony, all of which Judge VanDyke has bypassed
by introducing his factual testimony on appeal and alongside
his dissent. First, expert testimony must be found to “have a
reliable basis in the knowledge and experience of [the
expert’s] discipline” and be “more than subjective belief or
unsupported speculation.” Daubert v. Merrell Dow Pharms.,
Inc., 

 (1993). Should a party wish to
challenge the reliability of an expert’s conclusions, they may
move to exclude the expert’s testimony. District courts then
have an obligation to make an explicit finding as to an
expert’s reliability before permitting an expert to testify.
United States v. Jawara, 

 (9th Cir. 2007).
This gatekeeping function is vital “to make certain that an
expert, whether basing testimony upon professional studies
or personal experience, employs in the courtroom the same
level of intellectual rigor that characterizes the practice of an
expert in the relevant field.” Kumho Tire Co. v. Carmichael,

 (1999).
    Second, parties may contest an expert’s admission or
move to limit the scope of their testimony on the grounds
that the expert is insufficiently qualified to opine on specific
topics. See Fed. R. Evid. 702 (requiring that an expert
witness be “qualified . . . by knowledge, skill, experience,
training, or education”). Further, because expert testimony is
subject to general evidentiary rules, litigants may also seek
to exclude testimony on the basis that it is irrelevant, unduly
prejudicial, or otherwise objectionable under the Federal
Rules of Evidence. See, e.g., Fed. R. Evid. 401, 403.
                           DUNCAN V. BONTA                              67


     Third, various facets of expert testimony must be
disclosed during discovery to ensure that the litigants are on
notice of what evidence might be provided. These
disclosures include the identity of expert witnesses, the
subject of their testimony, and a summary of all of the facts
or opinions they intend to provide. Fed. R. Civ. P. 26(a)(2).
If the witness was specifically retained to provide testimony,
they must also provide a written report disclosing, among
other things, “a complete statement of all opinions the
witness will express and the basis and reasons for them,”
“the facts or data considered by the witness in forming
them,” “any exhibits that will be used to summarize or
support them,” and “the witness’s qualifications.” Fed. R.
Civ. P. 26(a)(2)(B). 6 Additionally, a litigant then has the
right to “depose any person who has been identified as an
expert whose opinions may be presented at trial.” Fed. R.
Civ. P. 26(b)(4)(A). These provisions ensure that litigants
are aware of the expert evidence that might be introduced,
allowing them to marshal objections, responses, or opposing
expert testimony.
     Aside from these mechanisms of exclusion and notice,
litigants have avenues for rebutting the contents of expert
testimony. They may cross-examine experts at trial or during
a deposition to challenge questionable aspects of their
testimony, qualifications, or methodology. See Fed. R. Evid.
611(b) (scope of cross-examination); id. 705 (disclosure of
expert witness’s underlying facts or data on cross-
examination). They may introduce facts that undercut the
expert’s credibility. See Fed. R. Evid. 607, 608. And they

6
 There are additional rules governing the timeliness of such disclosures
and requiring that they be updated with pertinent changes as the litigation
progresses. Fed. R. Civ. P. 26(a)(2)(B), (D).
68                     DUNCAN V. BONTA


can proffer competing evidence, often in the form of an
opposing expert witness. None of those avenues are
available when the “expert testimony” appears for the first
time in an appellate opinion.
    The procedures governing testimony generally and
expert testimony in particular are of paramount importance
to our adversarial system. Basic fairness demands that
parties have the opportunity to challenge the admissibility of
expert testimony, cross-examine expert witnesses, and
introduce countervailing evidence. Evidentiary and
procedural rules allowing parties to robustly analyze and
challenge expert witness testimony is critical to ensuring
factfinders are able to assess the veracity and reliability of
the technical evidence before them. Court evidentiary rules,
including the rules governing expert testimony, have
evolved over centuries to meet these purposes, adjusted over
time and interpreted in judicial opinions as gaps in coverage
appeared. See, e.g., Daubert, 

. Permitting
anyone—including a judge—to interject their observations
and opinions on technical factual issues without abiding by
these carefully developed rules for presentation of expert
testimony defangs these procedural safeguards and severely
disadvantages the litigants.
    Additional rules constrain the presentation of
demonstratives such as the firearms and related items that
Judge VanDyke features in his recording. Demonstratives
may be excluded if the court finds they are not relevant to
the matter at hand. See, e.g., United States v. Ortiz-Martinez,

 (8th Cir. 1993); United States v. Jones, 

 (7th Cir. 2000). A sufficient foundation must
be laid to verify that the demonstrative evidence is a fair and
accurate representation of what the witness claims it to be.
See, e.g., Keller v. United States, 

, 32 n.10 (1st
                       DUNCAN V. BONTA                      69


Cir. 1994); United States v. Myers, 

(11th Cir. 1992). Such demonstratives are excluded if the
court finds that their use would risk causing undue prejudice,
confusion, or delay. See Fed. R. Evid. 107, 403. Barring
exclusion, opposing counsel may address any inaccuracies
with the demonstrative through cross-examination. See, e.g.,
Roland v. Langlois, 

 (7th Cir. 1991)
(affirming use of a life-sized model where it “was admitted
only on the express condition that the jury be alerted to the
perceived inaccuracies”); Krause v. Cnty. of Mohave, 

, 1272–73 (D. Ariz. 2020) (explaining that an
illustrative animation’s “purported errors or inaccuracy can
be sufficiently addressed through jury instruction and cross-
examination”). Such demonstratives are also often subject to
disclosure requirements during discovery, to ensure the
parties are aware of what evidence might be presented. See
Fed. R. Civ. P. 26(a)(2)(B)(iii) (requiring expert reports to
include “any exhibits that will be used to summarize or
support” the expert witness’s opinions); 

(a)(3)(A)(iii)
(requiring disclosure of “each document or other exhibit,
including summaries of other evidence—separately
identifying those items the party expects to offer and those it
may offer if the need arises”).
    In providing a physical illustration of how various
handgun components function and how to replace them,
Judge VanDyke presents demonstratives that have not been
subject to the vetting procedures normally afforded such
evidence. Like Judge VanDyke’s procedurally infirm
factually based descriptions, commentary, and opinions, the
use of these demonstratives affronts party presentation
principles and flouts the rules that govern the introduction of
evidence.
70                     DUNCAN V. BONTA


                             III.
    Judge VanDyke presents his factual assertions not only
in the wrong court, but also with no regard to the well-
established requirements governing expert testimony and
demonstrative evidence. Moreover, his presentation is
doubly concerning because, had he provided his expert
testimony in the district court with all of the required
safeguards, he almost certainly would have needed to recuse
from adjudicating this matter on appeal. This recusal issue
most frequently arises in the context of district court judges,
who are flatly prohibited from serving as both arbiter and
witness. See Fed. R. Evid. 605 (“The presiding judge may
not testify as a witness at the trial.”); see also Quercia v.
United States, 

 (1933) (explaining that a
presiding judge “may analyze and dissect the evidence, but
he may not either distort it or add to it”); United States v.
Berber-Tinoco, 

 (9th Cir. 2007) (“[T]he
judge may not actually testify in the proceeding or interject
facts. . . .”). Moreover, “[a]ny justice, judge, or magistrate
judge of the United States shall disqualify himself in any
proceeding in which his impartiality might reasonably be
questioned.” 

(a). A reasonable observer
would be fair to question the impartiality of an appellate
judge who served as an expert witness in the proceedings
before the district court.
    Here, Judge VanDyke attempts to have it both ways:
providing a factual presentation with the express aim of
convincing both the parties and the panel of the truth of his
assertions, while also remaining a member of the panel
adjudicating the merits of the case. That Judge VanDyke
presents his factual commentary on appeal, as opposed to as
an expert witness in the proper forum, exacerbates rather
than cures the impropriety of the presentation. The form is
                       DUNCAN V. BONTA                       71


no different than it would have been had Judge VanDyke
sought to appear as an expert witness in district court, yet the
procedural protections the litigants would have had in
district court are totally absent.
    Contrast Judge VanDyke’s approach with that of the
majority. The defendants raised the question whether high-
capacity magazines may be considered an “accoutrement”
rather than an “arm” before the district court. Expert
opinions on that question were properly introduced before
the district court, are part of the record on appeal, and are
relied upon in the majority opinion. For example, in
analyzing the historical distinction between “arms” and
“accoutrements,” the majority draws from factual material
presented by an expert on corpus linguistics. Majority Op. at
26. Likewise, the majority relies on the declaration of a
firearms expert for the facts underlying its conclusion that
high-capacity magazines are accoutrements rather than
arms. Majority Op. at 28.
   The plaintiffs also introduced some pertinent evidence
on this issue. One of the plaintiffs’ experts opined that
magazines should not be considered accessories because
many firearms cannot function as intended without a
magazine during the district court proceedings. Another
gave a similar opinion based on his understanding of
magazine mechanics.
    Instead of relying on the factual material introduced by
the parties in the proper forum subject to the applicable
procedural rules, Judge VanDyke presents his own
testimony on the matter. He attempts to justify his eleventh-
hour factual interjections by asserting a need to refute the
“factual fantasy” underlying the majority’s test. But, as I’ve
noted, the majority’s test relied on factual submissions on
72                     DUNCAN V. BONTA


the accoutrement issue in the district court, record material
that Judge VanDyke ignores. Had plaintiffs wished to
proffer additional expert testimony, akin to that which Judge
VanDyke presents to support their argument against
classifying high-capacity magazines as accessories, they had
ample opportunity to do so.
    “In our adversarial system of adjudication, we follow the
principle of party presentation.” United States v. Sineneng-
Smith, 

 (2020). “[W]e rely on the parties
to frame the issues for decision and assign to courts the role
of neutral arbiter of matters the parties present.” 

 (quoting
Greenlaw v. United States, 

 (2008)). In
acting as a self-appointed expert, Judge VanDyke oversteps
his role as arbiter and robs the parties of their prerogative to
develop the record as they see fit, as well as the many
procedural protections to which they are entitled.
                       *       *       *
    Judge VanDyke might well be able to qualify as an
expert on guns. But whatever specialized expertise we bring
to the bench is irrelevant to our role as judges. Our job is not
to provide the facts that support our conclusions but to apply
the law to the facts as presented by the parties. Judge
VanDyke’s factual presentation flips this foundational
principle on its head.
    The majority is right to ignore the contents of Judge
VanDyke’s video presentation. These outside-the-record
assertions of fact, made by someone not properly admitted
as an expert or subject to any of the many procedural
safeguards that govern expert and demonstrative testimony,
have no bearing on the proper disposition of this appeal. And
while Judge VanDyke accuses the majority of “blinding
itself” to the facts he presented in his video, Dissent at 143,
                       DUNCAN V. BONTA                       73


limiting review to the facts presented by the parties is
precisely what appellate courts are required to do. See Fed.
R. App. P. 10.
    True, the prejudice to the parties here is arguably
minimal because Judge VanDyke has prepared his video in
support of a dissent. But if a dissent can rely on a judge’s
recorded factual presentation, nothing prevents a majority
opinion from doing the same thing. I therefore write
separately in the hope that in the future my colleagues,
whether in the majority or dissent, will do exactly and only
that: write. And, although I am surprised that it is necessary
to do so, I write to reemphasize that as judges, we must
decide cases as they are presented to us by the parties,
leaving advocacy to the attorneys and testimony to the
witnesses, expert and otherwise.


R. NELSON, Circuit Judge, dissenting:

    I agree with Judge Bumatay that the majority’s decision
to reverse the district court on the merits flouts New York
State Rifle & Pistol Association, Inc. v. Bruen, 

(2022). But the majority didn’t just butcher the Second
Amendment and give a judicial middle finger to the Supreme
Court. It also spurned statutory procedure for en banc
proceedings. As explained in my dissent from the order filed
concurrently with this opinion, this en banc court lacks
statutory jurisdiction to decide this new appeal, years after it
remanded the prior appeal to the district court. See
R. Nelson Dissent to Order at 69–76; Moody v. Albemarle
Paper Co., 

 (1974) (per curiam) (quoting

(c)).
74                         DUNCAN V. BONTA


    Every other circuit applies § 46(c) to require a new en
banc vote in a new appeal. As Judge Ikuta points out, the
majority’s view “is not the best interpretation of this statute,
in light of the history and purpose of an en banc
consideration.” Ikuta Special Concurrence to Order at 56–
57. Nor is the majority’s retention of this case business as
usual. See R. Nelson Dissent to Order at 59–60, 81–89.
Never before has a court allowed five senior judges to
control an en banc decision on behalf of the court’s active
judges. We shouldn’t have been the first, let alone in such
an important case. As Judge Bumatay notes, the majority’s
decision was a misuse even of our own rules. See Bumatay
Dissent to Order at 102. The result is a precedential Second
Amendment opinion that largely reflects the views of five
senior judges, not the active judges statutorily entrusted with
“determin[ing] the major doctrinal trends of the future” for
our court. Moody, 

 (quoting United States v.
Am.-Foreign S. S. Corp., 

 (1960)). That
does not bode well for public confidence in the courts—and
our court specifically.


BUMATAY, Circuit Judge, with whom IKUTA, R.
NELSON, and VANDYKE, Circuit Judges, join, dissenting:

    California is at the forefront of States seeking to limit
their citizens’ firearm rights. The State says its firearms laws
are the strictest in the Nation. 1 From an assault-weapons ban
to red-flag laws, from waiting periods to age restrictions and
universal background checks, California’s gun-control

1
  Official Website of the State of California, FACT SHEET: California’s
strong gun safety laws continue to save lives, (Jun. 7, 2024), available at:
https://perma.cc/W75M-U4GX.
                        DUNCAN V. BONTA                        75


measures significantly reduce its citizens’ access to firearms.
California believes these restrictions cut firearms-related
violence. 2 As a sovereign State, California may of course do
what it thinks proper to protect its citizens. But what
California may not do is encroach on its citizens’
constitutional rights. We cannot ignore that California’s
actions continually whittle away the Second Amendment
guarantee. While California may pass laws to address gun
violence, California’s choices must give way to the
Constitution.
    And this is true no matter how well-meaning the gun
control measures. It is easy to sympathize with the litany of
tragedies that California cites to justify its regulatory actions.
We understand California’s concern for needless gun
violence. We recognize California’s desire to curtail mass
shootings. And we appreciate that many will vehemently
disagree on policy grounds with enforcing the constitutional
limits on California’s gun-control measures.
     But, as federal judges, our duty is to uphold the
Constitution—no matter how unpopular. After all, the right
to keep and bear arms is a “fundamental right necessary to
our system of ordered liberty.” McDonald v. City of
Chicago, 

 (2010) (plurality opinion). And
through incorporation under the Fourteenth Amendment, the
Constitution authorizes only state regulations “consistent
with the Second Amendment’s text and historical
understanding.” N.Y. State Rifle & Pistol Assoc. v. Bruen,

 (2022). So while California seeks to limit its
citizens’ access to firearms—even with the best of
intentions—it is our duty to ensure that the Second
Amendment endures and that this ancient right of the people

2
    

76                    DUNCAN V. BONTA


is given its fullest breadth. Otherwise, we abdicate our role
to the whims of the political majority of the State.
    At issue is California’s ban on the possession of firearm
magazines capable of accepting more than ten rounds of
ammunition. See 

, 16740.
California prohibits the sale and purchase of these
magazines, 

 § 32310(a); it punishes the possession of the
magazines with a fine and up to one year of imprisonment,
id. § 32310(c); and it requires those who possessed the
magazines before the ban to remove, sell, or surrender them,
id. § 32310(d).
    California calls these magazines “large-capacity
magazines.” That term suggests that their capacities are
greater than the usual magazine. But, in truth, magazines
holding more than ten rounds are the most common
magazines in the country. They come standard with the most
popular firearms sold nationwide. As the district court
observed, “in the realm of firearms,” these magazines “are
possibly the most commonly owned thing in America.”
Duncan v. Bonta, 

, 1214 (S.D. Cal.
2023) (“Duncan VIII”). By the most conservative estimates,
more than a hundred million “large-capacity” magazines
exist in the country today. To put it into perspective, if
California’s law applied nationwide, then half of all
magazines in the United States would be taken from nearly
40 million Americans. And so these magazines should be
more accurately termed “standard-capacity magazines.”
Simply put, the ban deprives Californians of the most
popular firearm magazines for self-defense and other lawful
purposes. That’s what’s at stake for California’s citizens.
   Whatever the moniker, California’s absolute ban on
magazines with more than ten rounds of ammunition is both
                          DUNCAN V. BONTA                            77


“unusual” and an “outlier.” See Bruen, 

(Kavanaugh, J., concurring). They are lawfully possessed in
at least 38 States 3 and under Federal law. And California’s
law is novel. Aside from some Prohibition-era laws, 4 before
1990, only the District of Columbia restricted law-abiding
citizens’ possession of feeding devices of any size.



3
   Only twelve States and the District of Columbia ban the outright
possession of magazines with more than a certain number of rounds. See
California (

); Colorado (

-
12-301, 18-12-302) (limits magazine capacity to 15); Connecticut
(

-202w); Delaware (Del. Code tit. 11, §§ 1468,
1469) (limits magazine capacity to 17); the District of Columbia (

); Hawaii (

) (handguns only);
Illinois (720 Ill. Comp. Stat. 5/24-1.10) (10 rounds for “long guns” and
15 rounds for handguns); Massachusetts (Mass. Gen. Laws Ch. 140,
§§ 121, 131M); New Jersey (N.J. Stat. §§ 2C:39-1, 2C:39-3); New York
(

, 265.02); Oregon (

);
Rhode Island (

, 11-47.1-3); and Vermont
(Vt. Stat. tit. 13, § 4021) (10 rounds for “long guns” and 15 rounds for
handguns). Two other States forbid the manufacture and sale of these
magazines. See Maryland (Md. Code, Crim. Law § 4-305); and
Washington (

, 9.41.370).
4
   Michigan, Rhode Island, and Minnesota enacted laws limiting
magazine capacity in the 1920s and 1930s, but those laws were repealed
or amended and do not serve as a ban on magazine capacity today. See
Act of June 2, 1927, No. 373, § 3, 

, 888
(repealed 1959); Act of Apr. 22, 1927, ch. 1052, §§ 1, 4, 

, 256–57 (amended 1959); 1933 Minn. Laws ch. 190
(amended 1963). Only the District of Columbia’s 1932 restriction of
magazine capacity remains operative. See Act of July 8, 1932, 

 1, 8, 

, 650, 652. While it appears Virginia
may have defined “machine gun” to encompass guns able to fire sixteen
bullets without reloading, see ch. 96, §§ 1–7, 1934 Va. Acts 137–139,
Virginia has since amended the definition and the law no longer includes
this language. Va. Code § 18.2-288.
78                         DUNCAN V. BONTA


California’s possession ban just went into effect in 2017, and
three States enacted their laws in the last three years. 5
    Nothing in the historical understanding of the Second
Amendment warrants California’s magazine ban. Even with
some latitude in searching for historical analogues, none
exist. California points to no historical laws banning the
possession of firearms commonly used for self-defense.
Other traditional laws—like laws against carrying certain
weapons in public, laws against possessing particular
weapons, gunpowder storage laws, and laws against setting
trap guns—don’t remotely resemble the “how” and “why”
of California’s magazine bans.
    Thus, neither the text of the Second Amendment nor our
country’s historical tradition of firearm regulation supports
California’s magazine ban. Still, the majority once again
upholds California’s regulation. In doing so, the majority
defies the Supreme Court.
    First, the majority takes the extreme position that the
Second Amendment doesn’t even apply to California’s
magazine ban. That’s because the majority rules that
magazines holding more than ten rounds are not even
“Arms” under the Second Amendment. So California’s law
receives no constitutional scrutiny at all. And it bases this
ruling on the flimsiest ground. Somehow, the majority
believes that a “large-capacity magazine is no different than”
a “belt[] that hold[s] bullets.” Maj. Op. 28–29. Such a belief
displays ignorance of both firearms operations and
constitutional law. Indeed, the majority bases its “Arms”
analysis, in part, on a portion of a district court opinion
unanimously reversed by the D.C. Circuit. See id. at 23

5
    Oregon (2022), Rhode Island (2022), and Illinois (2023). See note 3.
                       DUNCAN V. BONTA                      79


(citing Hanson v. District of Columbia, 

,
14 (D.D.C. 2023), rev’d in part, 

, 232 (D.C.
Cir. 2024)). So not surprisingly, no other circuit court has
gone as far as the Ninth Circuit has in declaring that some
magazines fall outside the scope of the Second Amendment.
     Second, the majority makes up a new two-test Bruen
framework—the so-called “more nuanced approach” and the
“straightforward,” unnuanced approach. 

 at 37–41.
While giving little explanation for its invention, under the
“more nuanced approach,” the majority claims that there is
no need to look to historical analogues whenever we are
dealing with technological or societal change because
governments are simply entitled to “more flexib[ility]” in
limiting the Second Amendment right. 

. And under
its “straightforward” Bruen test, the majority interest-
balances its way into concluding that California’s ban
conforms with historical analogues. It draws the broadest
generalities from California’s claimed historical
analogues—fashioning a dubious tradition against
“especially dangerous” weapons. This supposed tradition is
no different from just requiring the State to provide a public-
safety rationale. But this ignores the admonition that
“court[s] must be careful not to read a principle at such a
high level of generality that it waters down the right.”
United States v. Rahimi, 

 (2024) (Barrett,
J., concurring). Ignoring this limitation, the majority then
finds a supposed match between that purported tradition and
California’s ban by improperly minimizing its burden on
self-defense. Under either of the majority’s created tests,
we’ve returned to interest balancing by another name. So
yet again, the majority continues to reject the Supreme
Court’s Second Amendment jurisprudence.
80                        DUNCAN V. BONTA


    We have repeatedly sounded the alarm over the affront
to the Second Amendment here. See Duncan v. Bonta, 

 (9th Cir. 2021) (en banc) (“Duncan V”)
(Bumatay, J., dissenting); Duncan v. Bonta, 

 (9th Cir. 2023) (en banc) (“Duncan IX”) (Bumatay, J.,
dissenting). 6 Over the course of this litigation, the majority
has taken at least three positions on how California’s novel
ban should be upheld as constitutional. So this is now the
third time we’ve had to warn against the majority’s violation
of Supreme Court instructions. We sound the alarm yet
again—but this time, it’s more dire given the extreme nature
of the majority’s ruling. Its implications are vast and lead to
a dangerous expansion of government power. In contrast, if
our analysis here sounds familiar, it is. Our position has
remained the same from the start of this litigation. Adhering
to the Second Amendment’s text and historical
understanding,       California’s     magazine       ban     is
unconstitutional.
    Because the majority’s ruling again stands in opposition
to the Second Amendment’s text, history, and tradition, we
respectfully dissent.
                                   I.
     THE SECOND AMENDMENT FRAMEWORK
    The Second Amendment commands that “[a] well
regulated Militia, being necessary to the security of a free
State, the right of the people to keep and bear Arms, shall
not be infringed.” U.S. Const. amend. II. This right flows
from the inherent right of self-defense—as Blackstone said,
it was central to “the natural right” to “self-preservation and

6
  This case has been up and down the federal courts so often that this is
the fourth decision by our en banc court in this saga.
                      DUNCAN V. BONTA                      81


defence.” District of Columbia v. Heller, 

, 593–
94 (2008) (quoting 1 William Blackstone, Commentaries on
the Laws of England 139–40 (1765)).
    Though the Second Amendment guarantees a
preexisting right, it took until Heller for the Supreme Court
to recognize its rightful place as a fundamental protection of
liberty. In Heller, the Supreme Court examined the
Amendment’s “text and history” and concluded that it
“conferred an individual right to keep and bear arms.” 

. Although “not unlimited,” at its core, the Second
Amendment protects the right of “law-abiding citizens” to
keep and carry arms for the “lawful purpose of self-defense.”

. This guarantee is at its strongest when
“arms” are used “in defense of hearth and home.” 

.
And because the right is so “deeply rooted in this Nation’s
history and tradition,” it is “fully applicable to the States”
under the Fourteenth Amendment. McDonald, 

 (simplified).
    Repeatedly, the Court has rejected “freestanding
interest-balancing” to resolve Second Amendment
questions. Heller, 

 (simplified); see also
McDonald, 

 (rejecting “judicial interest
balancing”). Despite the Court’s clear teachings, in Heller’s
wake, many courts—including our own—created two-step,
interest-balancing tests that inevitably stripped away the
Second Amendment right. See, e.g., Young v. Hawaii, 

, 783–84 (9th Cir. 2021) (summarizing our two-step
process and collecting cases), cert. granted, judgment
vacated, 

 (2022). As we’ve said, this two-
step approach proved to be mere “window dressing for
judicial policymaking.” Duncan V, 

(Bumatay, J., dissenting). At least in our court, no state
regulation had ever been ruled unconstitutional before
82                     DUNCAN V. BONTA


Bruen. See 

 (VanDyke, J., dissenting) (observing
the Second Amendment’s 0-for-50 record in the Ninth
Circuit).
    Then came Bruen. Having had enough of the balancing,
Bruen established a new framework—one consistent with
the text of the Constitution. Bruen expressly declared that
the “Constitution demands” that we jettison the use of
“interest balancing.” 

. Instead, it returned us
to the “Second Amendment’s text and historical
understanding.” 

 First, we look to the Second
Amendment’s textual elements: Does “the Second
Amendment’s plain text cover[] an individual’s conduct[?]”

. If so, “the Constitution presumptively protects that
conduct.” 

 Second, to rebut that presumption, the
government bears the burden of “justify[ing] its regulation
by demonstrating that it is consistent with the Nation’s
historical tradition of firearm regulation.” 

. Put
simply, the government “must affirmatively prove that its
firearms regulation is part of the historical tradition that
delimits the outer bounds of the right to keep and bear arms.”

. If the government fails to do this, the regulation
does not pass “constitutional muster.” 

.
    How do we know if a regulation fits in the historical
tradition? Like judges do in every case, we use analogical
reasoning. But rather than ask how other federal judges have
conducted the interest-balancing calculus, we apply “the
balance struck by the founding generation to modern
circumstances.” 

 at 29 n.7. That means the government
must “identify a well-established and representative
historical analogue,” and our task is to decide whether the
regulation and historical analogues are “relevantly similar.”

 (simplified). Of course, this “analogical
reasoning . . . is neither a regulatory straightjacket nor a
                       DUNCAN V. BONTA                      83


regulatory blank check”—some regulations will stand, some
will fall. 

.
     But the key is finding a relevantly similar historical
analogue. Analogues need not be “twin[s]” or “dead
ringer[s].” 

 Instead, Bruen tells us that our “central”
consideration is whether the modern regulation “impose[s] a
comparable burden on the right of armed self-defense” and
whether “that burden is comparably justified.” 

. In
other words, we must compare the “how” and the “why” of
the government’s regulation with the reported historical
analogue. 

 In this way, the only means-ends scrutiny
involved is the “interest balancing by the people” who
ratified the Second Amendment. Heller, 554 U.S. at 635.
    In conducting this inquiry, we shouldn’t be overly
rigid—we don’t have to look for “a law trapped in amber.”
Rahimi, 

. Instead, we look to “whether the
challenged regulation is consistent with the principles that
underpin our regulatory tradition.” 

 (emphasis
added). So what’s required is that the modern regulation
“works in the same way and does so for the same reasons”
as historical regulations.       

 (Gorsuch, J.,
concurring). Doing this faithfully may reveal guiding
principles defining the scope of the right. At the same time,
we must also “be careful not to read a principle at such a high
level of generality that it waters down the right.” 

(Barrett, J., concurring). After all, extracting principles too
far removed from the historical record just returns us to the
interest-balancing regime the Court has authoritatively
repudiated. And “[h]istory, not policy, is the proper guide.”

 (Kavanaugh, J., concurring).
84                    DUNCAN V. BONTA


                             II.
         CALIFORNIA’S MAGAZINE BAN IS
              UNCONSTITUTIONAL
   With this framework in mind, we turn to California’s
magazine ban.
     First, we examine whether the Second Amendment’s
“plain text” covers the conduct that California regulates.
Bruen, 

. It does. And because California’s
magazine ban fits within the Amendment’s textual elements,
it’s “presumptively” unconstitutional. 

.
    Second, we evaluate whether California has overcome
the presumption of unconstitutionality. It must do so by
justifying its law under our “historical tradition of firearms
regulation[s].” 

 It hasn’t. Thus, California’s magazine
ban is unconstitutional.
     A. California’s Magazine Ban is Presumptively
        Unconstitutional
    California’s ban prohibits people from owning,
possessing, purchasing, or selling any magazine holding
more than ten rounds, and forces people to surrender
magazines already in circulation to the government. See 

. As a result, California’s ban infringes
on the “right of the people” to “keep” and “bear” magazines.
Bruen, 

 (explaining that “bear” “naturally
encompasses” “carrying handguns publicly for self-defense”
and, at a minimum, “keep” means the possession of
“firearms in the[] home, at the ready for self-defense”).
Thus, California’s magazine ban easily fits into the Second
Amendment’s “textual elements,” which makes it
presumptively unconstitutional. Rather than accept this
obvious conclusion, the majority contends that these
                       DUNCAN V. BONTA                      85


magazines are not even “Arms” under the Second
Amendment. That’s wrong.
       1. Magazines Are “Arms”
    Magazines—whether they hold ten rounds, more than
ten rounds, or fewer than ten rounds—are unquestionably
“Arms” under the Second Amendment. As a textual matter,
“Arms” include any “[w]eapons of offence, or armour of
defence” or “any thing that a man wears for his defence, or
takes into his hands, or useth in wrath to cast at or strike
another,” that is “carr[ied] . . . for the purpose of offensive
or defensive action.” Heller, 

(simplified). Arms, then, “extends, prima facie, to all
instruments that constitute bearable arms, even those that
were not in existence at the time of the founding.” 

.
At a minimum, the meaning of Arms “covers modern
instruments that facilitate armed self-defense.” Bruen, 

.
    California’s ban applies to instruments that are necessary
to the operation of most modern firearms for self-defense. A
magazine is a “container or (detachable) receptacle in a
repeating rifle, machine-gun, etc., containing a supply of
cartridges which are fed automatically to the breech.”
Oxford English Dictionary Online (2024) (emphasis added).
As that definition makes clear, the magazine is a part of the
firearm. It stores and continuously feeds cartridges into the
firearm’s chamber. Firearms with detachable magazines—
the most commonly owned firearms—simply cannot fire as
designed without a magazine. Indeed, some firearms won’t
fire a single shot without an attached magazine. And so,
when a person uses a firearm in self-defense, the person must
operate both the firearm and magazine together. Without the
magazine, the firearm would be practically useless for self-
86                      DUNCAN V. BONTA


defense. Because magazines are a necessary component of
using firearms in self-defense, they are integral to a bearable
“instrument that facilitate[s] armed self-defense.” Bruen,

.
    By its nature, the Second Amendment’s protection of
“Arms” must extend to their functional components. If
magazines and other components weren’t included, the
Second Amendment would be a shallow right—easily
infringed by basic indirect regulation. But our fundamental
rights are more robust than that. Simply put, the government
can’t accomplish through “indirect[] infringement” what
would otherwise be a “direct interference with fundamental
rights.” See Healy v. James, 

 (1972); see
also Nat’l Rifle Ass’n of Am. v. Vullo, 

, 190
(2024) (“a government official cannot do indirectly what she
is barred from doing directly”).          Our Constitution thus
“implicitly protect[s] . . . closely related acts necessary to the
exercise” of enumerated rights. Luis v. United States, 

 (2016) (Thomas, J., concurring). After all,
“[t]here comes a point . . . at which the regulation of action
intimately and unavoidably connected with [a right] is a
regulation of [the right] itself.” Hill v. Colorado, 

 (2000) (Scalia, J., dissenting).
    That’s why the Second Amendment protects “necessary
concomitant[s]” to the right to bear arms. N.Y. State Rifle &
Pistol Ass’n, Inc. v. City of New York, 

(2020) (Alito, J., dissenting). So the Second Amendment’s
scope includes corollaries necessary to firearms’ use for self-
defense, like the right to learn how to “keep [firearms] ready
for their efficient use,” Heller, 

 (Breyer, J.,
dissenting) (simplified); the right to “obtain bullets
necessary to use” firearms, Jackson v. City & Cnty. of San
Francisco, 

 (9th Cir. 2014); and the “right
                       DUNCAN V. BONTA                      87


to possess the magazines necessary to render . . . firearms
operable,” Fyock v. Sunnyvale, 

 (9th Cir.
2015).
     And once properly understood as “Arms,” magazines of
all stripes, including those holding more than ten rounds, are
protected. After all, the government can’t limit the people
to government-preferred types of magazines any more than
it can limit the people to government-preferred types of
firearms. See Heller, 

 (holding that the
government can’t forbid handguns because long guns are
available).
   The majority sees things differently. Although the
majority begrudgingly concedes that magazines are
generally protectable “Arms” and that “large-capacity”
magazines “enhance[] . . . a person’s ability . . . to defend”
himself, Maj. Op. 29, it nonetheless excludes the “large-
capacity” magazine from the protection of the Second
Amendment. And it does so using questionable reasoning.
     Let’s try to explain the majority’s analysis. The majority
first draws a constitutional distinction between “Arms” and
“accoutrements.” According to the majority, “Arms” and
their necessary components are protected by the Second
Amendment, but accoutrements or firearm accessories are
not. Id. at 26. It then reasons that a magazine by itself isn’t
an “Arm[]” protected by the Second Amendment. That’s
because magazines are “harmless” when not attached to an
accompanying firearm and so they can’t “reasonably” be
described as a “weapon[] of offence, or armour of defence.”
Id. (quoting Heller, 

). Nor is a “large-
capacity” magazine a protected component of a firearm, says
the majority, because no firearm “requires” a magazine
holding more than ten rounds to “function normally.” 

 at
88                        DUNCAN V. BONTA


28. Stringing this altogether, the majority claims “large-
capacity” magazines are not “Arms” under the Second
Amendment. The majority’s analysis is flawed for at least
three reasons.
    First, a magazine is simply not an accoutrement—it’s a
necessary firearm component. No antebellum dictionary
describes “accoutrement” to include firearm components.
Instead, they define “accoutrement” as:

         •   “Attire, dress, garb, furniture.” Nathan
             Bailey, An Universal Etymological
             English Dictionary 21 (London, T.
             Osborne 1763).
         •   “Dress, equipage, furniture relating to the
             person; trappings, ornaments.” Samuel
             Johnson, A Dictionary of the English
             Language 5 (London, W. Strahan 1773).
         •   “[D]ress, habiliments, particularly after a
             warlike manner.” Thomas Dyche, A New
             General English Dictionary 24 (London,
             C. Bathurst 1777).
         •   “In a military sense, signify habits,
             equipage, or furniture, of a soldier, such
             as belts, pouches, cartridge-boxes,
             saddles, bridles, &c.” William Duane, A
             Military Dictionary 2–3 (Philadelphia, W.
             Duane 1810). 7


7
 In the military context, equipage “is all kinds of furniture made use of
by the army,” such as “tents, kitchen furniture, saddle horses, baggage
wagons, bat horses, &c.” See Duane, A Military Dictionary 139.
                      DUNCAN V. BONTA                     89


       •   “[I]n a military sense, signify habits,
           equipage, or furniture of a soldier, such as
           buffs, belts, pouches, cartridge boxes,
           &c.”     Charles James, An Universal
           Military Dictionary 3 (4th ed. 1816).
       •   “Dress; equipage; trappings; ornaments.”
           Samuel Johnson & John Walker, Johnson
           & Walker’s English Dictionaries 63
           (Boston, C. Ewer 1828).
       •   “Dress; equipage; furniture for the body;
           appropriately, military dress and arms;
           equipage for military service.” Noah
           Webster, American Dictionary of the
           English Language xv (New York, S.
           Converse 1828).
       •   “Equipage;    trappings;    ornaments.”
           Joseph Worcester, Primary Dictionary of
           the English Language 13 (Boston, Swan,
           Brewer, and Tileston 1861).

No modern magazine would fit within the definition of
“accoutrements.” And the size of the magazine wouldn’t
matter either. As a necessary component of the functioning
of a firearm, it’s not part of the “habits, equipage, or
furniture, of a soldier.” Duane, A Military Dictionary 2–3.
Under these definitions, magazines, including those holding
more than ten rounds, are not “accoutrements.” Instead, they
are protected components of “Arms,” like triggers and
barrels. Ignoring these facts, the majority merely asserts
magazines are no different than “cartridge boxes and belts
that hold bullets.” Maj. Op. 28–29.
90                      DUNCAN V. BONTA


    Second, the majority’s faux-Solomonic splitting of
magazines based on the number of rounds they hold makes
no sense. The majority concedes that magazines holding ten
or fewer rounds are perfectly legal, “integral” components
of “Arms”—entitled to the Second Amendment’s fullest
protection. Id. at 28; see also id. at 27 (“[T]he Second
Amendment’s text necessarily encompasses the corollary
right to possess a magazine . . . just as it protects the right to
possess ammunition and triggers.”). And common sense
dictates that just because a magazine holds more than ten
rounds doesn’t transform it into an accoutrement. Yet the
majority seems to possess magical abilities. See id. at 27.
As soon as you add one more round—poof—the magazine
is no longer “integral” and it disappears from the Second
Amendment’s ambit. Call this the “magic bullet” theory of
the Ninth Circuit.
    So the majority’s “Arms” versus “accoutrements”
distinction proves too much. Either a magazine is an
“accoutrement,” which States may ban completely under the
majority’s theory. Or it’s an “Arm[]” which affords it
Second Amendment protection. The majority can’t seem to
make up its mind on where magazines fit. The majority
won’t—and can’t—go so far to say that magazines may be
prohibited outright. But in the next breath it says some
magazines aren’t protected at all. This “accoutrement”
distinction is thus baffling and unhelpful. In the end, even
the majority abandons the distinction as it concedes that
some “accessories . . . are necessary for the ordinary
operation of a . . . weapon” and fall within the Second
Amendment’s protection. Id. at 27.
   Third, the majority misunderstands the Second
Amendment inquiry. According to the majority, “[t]he
proper inquiry . . . is whether the component or accessory is
                       DUNCAN V. BONTA                       91


necessary to the ordinary operation of the weapon, not
whether, when one voluntarily chooses to use an optional
accessory, the accessory is attached to the weapon.” Id. at
29. But that’s wrong. The “relevant test” under the Second
Amendment isn’t what’s strictly “necessary” for self-
defense. Rather, the Second Amendment inquiry centers on
what the people choose to “facilitate armed self-defense.”
Bruen, 

. As we’ve said before, “[l]awful
purpose, not necessity, is the test.” Duncan IX, 

 (Bumatay, J., dissenting).
     Indeed, the Supreme Court has already rejected the
majority’s strictly-necessary-for-self-defense theory of the
Second Amendment. In Heller, the government argued that
its handgun ban was permissible because it allowed citizens
to use long guns for self-defense. 554 U.S. at 629. So in the
government’s view, handguns weren’t strictly necessary
because citizens could defend themselves with other
weapons. The Court forcefully rejected that argument,

       It is no answer to say . . . that it is permissible
       to ban the possession of handguns so long as
       the possession of other firearms (i.e., long
       guns) is allowed. It is enough to note, as we
       have observed, that the American people
       have considered the handgun to be the
       quintessential self-defense weapon. . . .
       Whatever the reason, handguns are the most
       popular weapon chosen by Americans for
       self-defense in the home, and a complete
       prohibition of their use is invalid.
Id. Thus, the Second Amendment grants citizens the choice
of commonly owned arms to protect themselves. The
government doesn’t get to decide for the people.
92                     DUNCAN V. BONTA


    And we would never be so parsimonious when it comes
to other constitutional rights. Imagine granting only what’s
strictly necessary to enjoying the free-speech or free-
exercise right. No court would tolerate that. That’s like
saying that, as long as the government permits speech
through print or the airwaves, it may ban speech on social
media platforms because they’re mere “optional
accessories” for spreading information. See Meyer v. Grant,

 (1988) (“That [people] remain free to
employ other means to disseminate their ideas does not take
[restrictions on] their speech . . . outside the bounds of First
Amendment protection.”). It’s also like saying that the
government can ban religious worship at home because it’s
not strictly “necessary” when churches and synagogues are
available. See Tandon v. Newsom, 

 (2021). The
examples could go on and on. But it bears repeating—the
Second Amendment is no “second-class right, subject to an
entirely different body of rules than the other Bill of Rights
guarantees.” Bruen, 

 (simplified).
   Thus, the majority’s attempt to carve out magazines
holding more than ten rounds from the Second
Amendment’s protection of “Arms” is wrong both as a
matter of firearms operations and constitutional law.
       2. Common-Use Question
    For its part, California argues that Plaintiffs here failed
to satisfy their burden of proving that magazines holding
more than ten rounds are “in common use” for self-defense,
which it argues is part of Bruen’s step-one textual analysis.
Plaintiffs counter that the “common use” inquiry only comes
into play under Bruen step two and thus it’s California’s
burden to prove.         Concededly, “Bruen is somewhat
ambiguous on this point.” Bianchi v. Brown, 

,
                      DUNCAN V. BONTA                      93


501 (4th Cir. 2024) (Richardson, J., dissenting). It’s
mentioned in both the historical and textual steps of the
analysis. See Bruen, 

.
    This question has divided panels of our court. Compare
United States v. Alaniz, 

 (9th Cir. 2023)
(step one) with Teter v. Lopez, 

, 949–50 (9th Cir.
2023), vacated and reh’g en banc granted, 

(9th Cir. 2024) (step two). Indeed, during the preliminary
injunction stage, before the parties briefed this question, we
assumed that the “in common use” inquiry was part of the
Second Amendment’s “textual elements.” Duncan IX, 

 (Bumatay, J., dissenting). Besides, the question
of the common usage of these magazines is undebatable—
so, for this case, it didn’t matter which side carried the
burden of proof.
   Even so, after further briefing on the matter, we agree
with Plaintiffs “that the ‘common use’ inquiry best fits at
Bruen’s second step.”         Bianchi, 111 F.4th at 502
(Richardson, J., dissenting). We think this for three reasons.
    First, Bruen explained that the first step—whether the
Second Amendment presumptively protects conduct—
comes from determining whether the “plain text” of the
Second Amendment covers the conduct at issue. 

. And, as a textual matter, nowhere in the text of the
Second Amendment does “in common use” appear. See
Bevis v. City of Naperville, 

 (7th Cir.
2023) (Brennan, J., dissenting) (The Second Amendment
should be “read as ‘Arms’—not ‘Arms in common use at the
time.’”). Nor is common usage an inherent part of the
definition of “Arm,” which looks only at whether it’s a
bearable “[w]eapon[] of offence, or armour of defence.”
Heller, 

. Conducting the common-use
94                         DUNCAN V. BONTA


inquiry at the first step “would be at odds with the fact that
the common-use test is not about the semantic meaning of
the Second Amendment’s plain text.” J. Joel Alicea, Bruen
Was Right, 174 U. Pa. L. Rev. (forthcoming 2025)
(manuscript at 12). 8
    Second, under Bruen’s second step, the Second
Amendment permits only firearm regulations “consistent
with this Nation’s historical tradition.” 

. And
whether a firearm is “dangerous and unusual” or “in
common use” is borne from the “historical understanding of
the Amendment.” 

. Heller itself directly tied the
common-use inquiry to “the historical tradition of
prohibiting the carrying of dangerous and unusual
weapons.” 554 U.S. at 627 (simplified). Indeed, the “in
common use” phrase originates from United States v. Miller,

, 179 (1939), in which the Court described the
types of weapons colonial citizens would bring to militia
service.
    Third, as a matter of constitutional law, it makes sense
that California carries the burden of disproving “common
use.” As the Court has repeatedly said, the Second
Amendment is a fundamental individual right. Once a
plaintiff makes “a prima facie showing of arguable
[fundamental-right] infringement,” like in the First
Amendment context, the burden shifts to the government to
justify the regulation. See Brock v. Loc. 375, Plumbers
Intern. Union of Am., AFL-CIO, 

, 349–50 (9th
Cir. 1988) (simplified). In the First Amendment context, the
government’s burden is also “extraordinarily heavy.” ACLU
of Nev. v. City of Las Vegas, 

 (9th Cir.
2006). So too here. Once a prima facie showing of a Second

8
    Available at https://perma.cc/KV22-25HU.
                       DUNCAN V. BONTA                       95


Amendment infringement occurs (by showing the
government regulates conduct within the Amendment’s
“textual elements”), everything else falls on the government.
Since common usage of a firearm isn’t necessary to prove a
prima facie Second Amendment infringement, it’s the
government’s burden to carry at the second step.
   We turn there now.
   B. California Fails to Overcome the Presumption of
      Unconstitutionality
    Because the plain text of the Second Amendment
protects the possession of magazines capable of feeding
more than ten rounds, California’s ban is presumptively
unconstitutional. To rebut this presumption, California must
“justify its regulation” by proving that its ban fits within our
“historical tradition of firearm regulation.” Rahimi, 

 (quoting Bruen, 

). California
doesn’t meet its burden.
    California supports its magazine ban based on five broad
categories of historical analogues: (1) the prohibition of
“dangerous and unusual” weapons; (2) laws regulating the
carry of certain weapons; (3) prohibitions on possessing
crossbows, slungshots, and automatic firearms; (4) bans on
the setting of trap guns; and (5) regulations on the storage of
gunpowder. But given that California strictly bans the
ownership, possession, and use of magazines in common use
today, these traditions are not “relevantly similar” to justify
California’s magazine ban.
       1. Prohibition of “Dangerous and Unusual”
          Weapons
   Start with prohibitions on “dangerous and unusual”
weapons. From Miller to Heller to Bruen, the Supreme
96                    DUNCAN V. BONTA


Court has recognized that the “Second Amendment protects
only the carrying of weapons that are those ‘in common use
at the time,’ as opposed to those that ‘are highly unusual in
society at large.’” Bruen, 

 (simplified). As
the Court has explained, this understanding is “fairly
supported by the historical tradition of prohibiting the
carrying of ‘dangerous and unusual weapons.’” Heller, 

. Thus, the Court has suggested that “dangerous
and unusual” weapons fall outside the Second Amendment’s
protection. So if California can prove that these magazines
are “highly unusual” today, then that would be enough to
satisfy its burden.
    But the magazines California bans are the furthest thing
from highly unusual in modern America. In fact, firearms
with magazines holding more than ten rounds are the
overwhelming choice of Americans for self-defense and
other lawful purposes. While estimates vary, easily more
than 100 million of these magazines exist in the country.
According to one estimate, these magazines account for half
of all American magazines—that’s 115 million out of 230
million magazines in circulation today. See Duncan VIII,
695 F. Supp. 3d at 1217. Another estimate suggests that
these magazines are even more prevalent—climbing to a
staggering 542 million rifle and handgun magazines in the
hands of “millions of Americans across the country.” Id. at
1216–17. Indeed, Plaintiffs assert, and California doesn’t
contradict, that nearly 40 million Americans own or have
owned magazines with capacity for more than ten rounds—
that’s more than 10% of the Nation’s total population and
about half of all American gun owners. See William
English, Ph.D., 2021 National Firearms Survey: Updated
Analysis Including Types of Firearms Owned 22–23 (Sept.
                      DUNCAN V. BONTA                      97


28, 2022). Given this widespread ownership, they are
necessarily used for lawful purposes.
    And this common usage is nothing new. As we’ve said
before, a “clear picture emerges [from our history] that
firearms with large-capacity capabilities were widely
possessed by law-abiding citizens by the time of the Second
Amendment’s incorporation.” Duncan V, 

(Bumatay, J., dissenting). And “large-capacity” magazines
had become “common” in this country by at least “the late
nineteenth century or early twentieth century.” 

(Berzon, J., concurring). In contrast, regulation of these
magazines is unusual and new. As mentioned above, three-
quarters of all States have no magazine-capacity limit like
California.      The federal government’s short-lived
experiment with a magazine ban lapsed by 2004. See 

 Stat. 1796 (1994) (formerly codified at

(w)). Aside from D.C.’s law, most state bans
were enacted after the 1990s, with many passed in just the
last few years.
    Neither California nor the majority seriously challenge
that these magazines are “in common use.” Instead, the
majority buries the data. It claims that looking at
“ownership[]statistics” is too “simplistic” and disregards
reliance on them as too “rigid.” Maj. Op. 57. But, as lower
court judges, we are not free to set aside the Supreme Court’s
directions so easily. Heller and Bruen were very clear—
once a firearm is “in common use,” it falls out of the
historical tradition of prohibiting “dangerous and unusual”
weapons and is entitled to constitutional protection unless
restricted by another tradition.
   In Heller, the Court held that, because “handguns are the
most popular weapon chosen by Americans for self-defense
98                    DUNCAN V. BONTA


in the home,” they are protected by the Second Amendment
and their “complete prohibition” is “invalid.” 554 U.S. at
629; see also id. at 628–29 (“[A] prohibition of an entire
class of ‘arms’ that is overwhelmingly chosen by American
society for [the] lawful purpose” of self-defense “fail[s]
constitutional muster.”).     On the other hand, Heller
recognized that “the Second Amendment does not protect
those weapons not typically possessed by law-abiding
citizens for lawful purposes[.]” Id. at 625.
    Bruen put an even finer point on this question.
Assuming that historical laws could show handguns were
considered “dangerous and unusual” in our Nation’s past,
Bruen said that this history wasn’t dispositive when
handguns are “in ‘common use’ for self-defense today.” 

. So, “even if [historical] laws prohibited the
carrying of handguns because they were considered
‘dangerous and unusual weapons’” sometime in the past,
“they provide no justification for laws restricting the public
carry of weapons that are unquestionably in common use
today.” 

    So the lesson of Heller and Bruen is that the historical
tradition of banning “dangerous and unusual” weapons can’t
justify regulation of firearms in common use today. And
because these magazines are no doubt in common use today,
a tradition of banning weapons that “are highly unusual in
society at large” can’t support California’s magazine ban.
    Next, the majority tries a different tack. Again, ignoring
the Supreme Court’s instructions, the majority claims that
our historical tradition included dispossessing the people of
“especially dangerous” weapons—no matter how commonly
they were used for self-defense. Maj. Op. 12. Again, that’s
wrong. The Court has always grouped “dangerous and
                       DUNCAN V. BONTA                      99


unusual” together. See Heller, 

; Bruen, 

; see also Caetano v. Massachusetts, 

 (2016) (Alito, J., concurring) (“[T]his is a
conjunctive test: A weapon may not be banned unless it is
both dangerous and unusual.”). In other words, whether a
weapon is “dangerous and unusual” or “in common use” are
different sides of the same coin. See Bruen, 

(contrasting “dangerous and unusual weapons” with those
that are “in ‘common use’ for self-defense today”); Heller v.
District of Columbia, 

 (D.C. Cir. 2011)
(Kavanaugh, J., dissenting) (observing that the Supreme
Court “said that ‘dangerous and unusual weapons’ are
equivalent to those weapons not ‘in common use’”)
(simplified).
    Indeed, like the majority here, the dissent in Heller tried
to justify the D.C. handgun ban by arguing that an “outright
prohibition” is necessary “where a governmental body has
deemed a particular type of weapon especially dangerous.”
Heller, 

 (Breyer, J., dissenting). Of course,
the Court rejected this view. And since it didn’t work against
commonly used handguns, it won’t work against commonly
used magazines. Perhaps trying to evade Heller’s clear
ruling, the majority tries a new twist—recharacterizing the
tradition as a ban on “especially dangerous uses of weapons
once the threat to innocent persons has become clear.” See
Maj. Op. 49–50. But that move fools no one. It is simply a
retread of the same argument. And the bottom-line is this—
neither the majority nor California has identified any
historical regulation dispossessing law-abiding citizens of
commonly used weapons for self-defense because they were
“especially dangerous.” So this purported “tradition” is
made of thin air.
100                    DUNCAN V. BONTA


       2. Laws Regulating the Carry of Weapons
     California next relies on the tradition of regulating the
public carry of certain weapons to justify its regulation. To
be sure, these types of laws have been around a while. Anti-
carry laws trace back to 14th-century England as well as
colonial, Founding-era, and antebellum America. These
historical regulations, of course, differed. Most forbade
concealed carry, while some forbade open carry for certain
illicit purposes—reflecting the sensibilities of the
jurisdiction at the time. Only a few banned all public carry
of specific weapons, while others required intent—whether
the carry was meant to frighten or threaten. The throughline
of all these regulations, however, is that none broadly
disarmed law-abiding citizens.
    California begins with the Statute of Northampton of
1356. As Blackstone described the English law, the Statute
prohibited the “offence of riding or going armed, with
dangerous or unusual weapons,” while “terrifying the good
people of the land.” 4 William Blackstone, Commentaries on
the Laws of England, *148–49 (Wilfrid Prest et al. eds., 1st
ed. 2016). Although it was “centrally concerned with the
wearing of armor,” it’s accepted that it applied to weapons
like the “launcegay.” Bruen, 

. To the Court,
the Statute was notable for two reasons. First, the Statute
didn’t apply to common weapons—like medieval daggers—
which would be “most analogous to modern handguns.” 

. Second, the Statute applied only to those who carried
weapons “with evil intent or malice.” 

. Yet,
California’s ban applies to everyone—regardless of intent.
All in all, the Court concluded that English law couldn’t
“justif[y] restricting the right to publicly bear arms,” such as
handguns, “for self-defense” today. 

.
                          DUNCAN V. BONTA                           101


    The earliest American law cited by California dates to
1686. Then, the Quaker province of East New Jersey
prohibited the concealed carrying of “pocket pistol[s],
skeines, stilladers, daggers or dirks, or other unusual or
unlawful weapons” because they induced “great fear and
quarrels.” Grants, Concessions, and Original Constitutions
of the Province of New Jersey 289–290 (1881).
Massachusetts followed with other carry regulations—
although it only targeted armed groups. See An Act for
preventing and suppressing of Riots, Routs, and unlawful
Assemblies, 

, ch. 17 § 1 (prohibiting
being armed with “clubs or other weapons” in a group of
twelve or more); An Act to Prevent Routs, Riots, and
Tumultuous assemblies, and the Evil Consequences
Thereof, 

, ch. 38, 88 (same). California
claims that other States enacted “anti-carry laws” for clubs
and other blunt instruments.
    California next looks to historical laws limiting the carry
of bowie knives, concealed weapons, and pistols. California
contends that, by 1840, a handful of States implemented
laws regulating the carry of bowie knives, 9 and that those
restrictions eventually spread to most States by the end of


9
  As examples, California points to an 1836 Tennessee statute and 1839
Alabama statute. But neither law was a sweeping ban on the carry of
bowie knives. The Tennessee law only prohibited “wear[ing]” a bowie
knife “under his clothes” or otherwise “keep[ing it] concealed about his
person;” selling bowie knives, and “cut[ting] or stab[bing] another
person” with a bowie knife. See 1837-38 Tenn. Pub. Acts 200-01, An
Act to Suppress the Sale and Use of Bowie Knives and Arkansas Tooth
Picks in this State, ch 137, §§ 1, 2, 4. And the Alabama law only
regulated the “concealed” carry of “any bowie knife” and “any species
of fire arms.” 1839 Ala. Acts 67, An Act to Suppress the Evil Practice
of Carrying Weapons Secretly, § 1.
102                        DUNCAN V. BONTA


the 19th century. 10 California also observes that by 1838, a
handful of States had laws banning the concealed carrying
of weapons, such as pistols, dirks, sword canes, and spears. 11
Finally, according to California, several States responded to
an upswing in violence from the proliferation of
“percussion-cap pistols” in the first half of the 19th century
by restricting the carry of concealable pistols. The majority
identifies two late-19th century laws banning the carry of
concealable pistols. See Maj. Op. 44 (citing An Act to
Preserve the Peace and to Prevent Homicide, 

, ch. 90, § 1; An Act to Preserve the Public
Peace and Prevent Crime, 

, chap. XCVI,
§ 1-2). Interestingly, courts in Tennessee and Arkansas
struck down early versions of the laws because they applied
to repeating or military-style revolvers. See Andrews v.
State, 

 (1871) (holding that if the state law
applied to “the pistol known as the repeater,” “then the
prohibition of the statute is too broad to be allowed to

10
   California has identified no state laws banning the possession of bowie
knives. An 1837 Georgia act declared that, along with prohibiting carry,
a person cannot “keep, or . . . have about their person or elsewhere . . .
[a] Bowie, or any other kind of knives.” An Act to Guard and Protect
the Citizens of this State, Against the Unwarrantable and too Prevalent
Use of Deadly Weapons, 

, § 1. But in 1846, the
Georgia Supreme Court held the act unconstitutional “inasmuch” as it
“deprive[d] the citizen of his natural right of self-defence.” Nunn v.
State, 

 (1846) (suggesting the ruling applied to all
provisions of the act except concealed carry).
11
  These States were Kentucky (1813), Louisiana (1813), Indiana (1820),
Georgia (1837), Arkansas (1838), and Virginia (1838). See Clayton E.
Cramer, Concealed Weapons Laws of the Early Republic: Dueling,
Southern Violence, and Moral Reform 143–51 (1st ed. 1999). California
also often refers to the Duke Center for Firearms Law’s Repository of
Historical Gun Laws for sourcing. Available at https://perma.cc/E7FZ-
PANH.
                       DUNCAN V. BONTA                      103


stand”); Wilson v. State, 

, 559–60 (1878)
(concluding that “prohibit[ing] the citizen from wearing or
carrying [an army size pistol, such as are commonly used in
warfare,] is an unwarranted restriction upon his
constitutional right to keep and bear arms”).
    Regardless of a tradition to regulate the carry of certain
weapons, these laws cannot justify California’s ban on the
ownership and possession of magazines holding more than
ten rounds. Bruen dictates this conclusion. In that case, New
York relied on the same regulatory history as California to
show that States may restrict the public carry of firearms.
The Court agreed that “[t]he historical evidence from
antebellum America . . . demonstrate[s] that the manner of
public carry was subject to reasonable regulation.” Bruen,

 (simplified). Even so, that robust history was
not enough “to prevent law-abiding citizens with ordinary
self-defense needs from carrying arms in public.” 

.
     The answer is simple then: if historical regulation of the
carry of certain weapons in certain situations was not
“relevantly similar” to a modern law prohibiting the carry of
all weapons without a license, then those laws cannot be
analogous to California’s law preventing law-abiding
citizens from possessing firearms for self-defense purposes.
Put differently, if targeted historical carry laws don’t justify
wide-ranging restrictions on the carry of commonly owned
weapons, they don’t support the outright ban of commonly
owned weapons.
    Under Bruen, we can’t extrapolate from narrow
regulations a justification for much broader regulations.
While anti-carry laws “limited the intent for which one could
carry arms, the manner by which one carried arms, or the
exceptional circumstances under which one could not carry
104                    DUNCAN V. BONTA


arms,” 

, California’s law prohibits all conduct at all
places at all times, even in the privacy of the home. And
Heller made clear that the need for “defense of self, family,
and property is most acute” in “the home.” 554 U.S. at 628;
see also id. at 635 (The Second Amendment “surely elevates
above all other interests the right of law-abiding, responsible
citizens to use arms in defense of hearth and home.”). While
historical carry restrictions may burden the Second
Amendment right in one limited fashion, California’s
magazine ban is different in scope—it’s a complete
dispossession of a commonly owned “Arm.”
    Rahimi further signals the mismatch between the
tradition of carry regulations and California’s magazine ban.
In Rahimi, the Court determined that historical “surety laws”
and “going armed laws” supported the modern regulation of
disarming those under a domestic-violence protection order.
See 

(g)(8)(C)(i). That’s because both the
historical tradition and the modern regulation shared the
same “how” and “why.” Both served the purpose of
disarming “individuals found to threaten the physical safety
of another.” Rahimi, 

. And their burdens
were comparable—the temporary disarmament after a
judicial determination of a “particular defendant[’s]”
dangerousness. 

. In contrast, Rahimi observed that
the law struck down in Bruen “broadly restrict[ed] arms use
by the public generally.” 

. So while a tradition of
targeted and temporary disarming of dangerous individuals
may exist, that wouldn’t justify any broad-based, permanent
dispossession. So too here. Limited historical laws designed
to prevent confrontation, fear, and terror in public can’t
justify a modern law that prevents all individuals from ever
possessing a commonly owned arm for self-defense. In
other words, we can’t extract any “principles” from the
                        DUNCAN V. BONTA                         105


tradition of carry laws to fully dispossess law-abiding
citizens of arms in common usage. 

.
        3. Laws Banning Possession of Certain Weapons
    California also identifies a handful of laws throughout
history that banned the outright possession of a weapon.
None are a “relevantly similar” analogue to California’s
magazine ban.
    California cites an English law from 1541 that prohibited
persons with an annual income below 100 pounds from
possessing a crossbow without a license. See An Act
Concerning Crossbows and Handguns, 

, ch. 6, § 1,
(1541). This law is closer to California’s law since it appears
to prohibit outright possession of a weapon—at least for
certain classes of people. But by the 1700s, this law was
widely considered “obsolete” and so restrictive that the
Court considered the law as “not incorporated into the
Second Amendment’s scope.” Bruen, 

 n.10.
     California points to late 19th-century state laws against
slungshots. “Slungshots” refers to a wide range of hand-held
weapons for striking—often with a metal or stone attached
to a flexible strap or handle made of rope, leather, or other
material. Between 1849 and 1890, nine jurisdictions
prohibited the sales and manufacture of slungshots. 12 Only
Illinois banned their outright possession, while the other



12
  Vermont (1849), New York (1849), Massachusetts (1850), Kentucky
(1856), Florida (1868), Dakota Territory (1877), Illinois (1881),
Minnesota (1886), and Oklahoma Territory (1890). See David Kopel &
Joseph Greenlee, History of Bans of Types of Arms Before 1900, 50 J.
of Legis. 226, 346 (2024).
106                        DUNCAN V. BONTA


jurisdictions prohibited their carry. 13 Most other states
enacted laws against the carry of slungshots by the late 19th
century.
    Even if these laws come from the historically relevant
period, they don’t serve as proper analogues for California’s
magazine ban. Simply, slungshots were not commonly used
for self-defense. As California’s expert observed, they were
“widely used by criminals and street gang members,” with
no noted historical use for self-defense. Indeed, according
to one source, while “[c]ourt records of the [1800s] have
many cases of civilians . . . using slungshots,” “a man
bringing one out after being threatened comes up rarely.”
Kopel & Greenlee, 50 J. of Legis. at 345 (quoting Robert
Escobar, Saps, Blackjacks, and Slungshots: A History of
Forgotten Weapons 131 (2018)). So these slungshot
regulations don’t evince a historical justification for
regulating weapons that are used to “facilitate armed self-
defense” or other lawful purposes. See Bruen, 

. Further, the burdens of slungshot regulations and
California’s magazine restriction are dissimilar.
Historically, most States restricted only the carry of
slungshots—very different than an outright ban. Just one
State banned their possession—not enough to suggest a
widespread historical tradition. See Bruen, 

(“[W]e will not stake our interpretation of the Second
Amendment upon a law in effect in a single State, or a single
city, ‘that contradicts the overwhelming weight of other
evidence regarding the right to keep and bear arms[.]’”
(simplified)).


13
   

 A Vermont law from 1849 made it a felony to possess or carry a
slungshot for the “purpose of using it against another person.” Id. at 347.
                       DUNCAN V. BONTA                     107


    Finally, California raises 20th-century restrictions on
automatic and semi-automatic firearms as historical
analogues. According to California, from 1927 to 1934, over
a dozen States restricted fully automatic and some
semiautomatic firearms. We can make short work of this
argument. These laws were enacted nearly 140 years after
the Second Amendment’s ratification and 60 years after its
incorporation. That’s simply too late to help define the
meaning and scope of the Second Amendment right. The
Supreme Court has made clear that our inquiry of regulations
is at most cabined to the period “through the end of the 19th
century.” Bruen, 

 (quoting Heller, 

). And even then, late 19th-century history may be too
distant. See Bruen, 

 (Barrett, J., concurring)
(“[T]oday’s decision should not be understood to endorse
freewheeling reliance on historical practice from the mid-to-
late 19th century to establish the original meaning of the Bill
of Rights.”). So we can safely say that the 20th century is
not a relevant timeframe for this inquiry.
    In sum, this survey of history shows no robust historical
tradition of disarming law-abiding citizens of commonly
owned arms used for self-defense. Indeed, the lack of
outright weapons bans is telling in itself. From colonial
America to Founding-era America to antebellum America,
save an outlier or two, no laws banned the possession of any
type of weapon. It’s even starker when looking at firearms
bans. As the district court observed, between 17th-century
English laws and 19th-century state laws, California “has not
identified any law, anywhere, at any time . . . that prohibited
simple possession of a gun or its magazine or any container
of ammunition (unless the possessor was an African-
American or a slave or a mulatto).” Duncan VIII, 695 F.
Supp. at 1242. So if anything is “trapped in amber” here,
108                       DUNCAN V. BONTA


Rahimi, 602 U.S. at 691, perhaps it’s the historical
understanding that law-abiding citizens may choose any
commonly owned firearm for self-defense without
government interference. See Alicea, 174 U. Pa. L. Rev
(manuscript at 41) (“[T]he tradition of banning dangerous
and unusual weapons—and the absence of a tradition of
banning weapons in common use—is very strong (if not
dispositive) evidence that prohibiting arms in common use
by persons protected under the Second Amendment is per se
impermissible[.]”).
        4. Laws Against Trap Guns
    California’s reliance on trap-gun regulations is even
more far afield. Trap guns were contraptions using string,
wire, or other contrivances to remotely discharge a firearm.
Historically, they were used to thwart thieves from robbing
businesses or properties and sometimes for hunting.
According to California, only eleven States regulated trap
guns before the 20th century. 14 And only one was from the
18th century. New Jersey’s 1771 law banned “a most
dangerous Method of setting Guns.” 1763–1775 N.J. Laws
346, An Act for the Preservation of Deer and Other Game,
and to Prevent Trespassing with Guns, ch. 539, § 10. The
rest of these laws came into effect in the mid- to late-19th
century.
    Even assuming these laws are temporally significant,
they would not implicate the Second Amendment. Trap-gun
mechanisms aren’t protectable “Arms” under the Second

14
   According to California, those States are Michigan (1875), Minnesota
(1873), Missouri (1891), New Jersey (1771), New York (1870), North
Dakota (1891), Rhode Island (1890), South Carolina (1855), Utah
(1865), Vermont (1884), and Wisconsin (1872). We assume this record
is accurate.
                       DUNCAN V. BONTA                       109


Amendment’s text. To start, they are not “bearable.” See
Heller, 

 (“[T]he Second Amendment extends,
prima facie, to all instruments that constitute bearable
arms[.]”). On the contrary, the whole design of the trap gun
was to allow a firearm to be discharged without a person
needing to “keep” or “bear” it. So trap guns are not weapons
to “wear, bear, or carry . . . upon the person or in the clothing
or in a pocket, for the purpose . . . of being armed and ready
for offensive or defensive action in a case of conflict with
another person.” 

 (simplified). Nor can a person
take a trap gun “into his hands, or useth in wrath to cast at or
strike another.” 

. And they are not integral
components of a firearm. So the majority is just simply
wrong to claim that the trap guns were used for armed self-
defense. Indeed, the majority mistakenly suggests that
homeowners rigged trap guns in “defen[se]” of their
“homes.” Maj. Op. 42. But nothing in the record supports
that trap guns were used in such an improper way. Given all
this, it’s hard to see how trap guns fall under the Second
Amendment’s textual elements.
    But even if trap guns constitute “Arms,” the burdens of
regulating trap-gun mechanisms are not analogous to the
burdens of California’s magazine ban. First, California
identifies no historical regulation that prohibited the
possession of a trap-gun. Like New Jersey’s law, most
States prohibited only the setting of the device. See Kopel
& Greenlee, 50 J. of Legis. at 365–366. Other States only
forbade their setting for hunting or for injuring another
person. 

 But the broad dispossession of an arm is
different from preventing individuals from rigging a firearm
with a contraption to fire it automatically.
    The “why” of trap gun regulations is also very different.
As the majority must concede, these regulations were meant
110                   DUNCAN V. BONTA


to prevent the occasional tripping of trap guns by innocent
persons. California didn’t ban magazines holding more than
ten rounds to limit accidental firearms deaths. Rather, the
purpose of the magazine ban was to respond to intentional
gun violence.
       5. Laws Regulating Gunpowder Storage
    Finally, California relies on 18th- and 19th-century
gunpowder-storage laws. Concerned with the dangers of
massive fires and explosions, these laws prohibited the
stockpiling of large quantities of gunpowder in one place.
An 18th-century law, for example, made it unlawful in New
York City “to have or keep any quantity of gun powder
exceeding twenty-eight pounds weight, in any one place, less
than one mile to the northward of the city hall[.]” 

, An Act to Prevent the Danger Arising from the
Pernicious Practice of Lodging Gun Powder in Dwelling
Houses, Stores, or Other Places, ch. 28. Another 1821
Maine law regulated how much gunpowder could be
possessed and stored by a person “for the prevention of
damage by Fire.” 1821 Me. Laws 98–99, An Act for the
Prevention of Damage by Fire, and the Safe Keeping of Gun
Powder, ch. 25.
    These gunpowder-storage restrictions don’t establish a
historical tradition supporting California’s magazine ban.
First, these laws offer no comparable burden on the
possession of a firearm. While California’s magazine ban
prohibits using the most popular magazine for self-defense,
the gunpowder laws had zero effect on self-defense. They
“did not clearly prohibit loaded weapons” and “required only
that excess gunpowder be kept in a special container or on
the top floor of the home.” Heller, 554 U.S. at 632
(emphasis added). So they regulated the accumulation of
                     DUNCAN V. BONTA                   111


excess explosive material by limiting where it could be
stored—they didn’t prevent citizens from having
ammunition at the ready for self-defense. As the Supreme
Court observed when this history was used to defend a
handgun ban, “[n]othing about th[e]se fire-safety laws
undermines our analysis” because “they do not remotely
burden the right of self-defense as much as an absolute ban
on handguns.” Id.
   Second, the “why” is also obviously different. These
laws targeted the danger of accidental explosions and
widespread fire posed by improperly stored gunpowder. In
contrast, California’s purpose in enacting its ban was to
reduce intentional gun violence.
   So this tradition doesn’t support California’s magazine
ban.
                           ***
    In sum, the right to keep and bear firearms that use a
magazine able to hold more than ten rounds is presumptively
protected by the text of the Second Amendment. These
magazines constitute “Arms” because they are necessary
components of firearms and facilitate the firing process.
Thus, California had the burden of identifying a historical
analogue that is relevantly similar to a ban on these
magazines—and has failed to do so. Simply, no historical
analogue justifies California’s absolute ban on magazines
that come standard with most firearms. While “dangerous
and unusual” weapons may fall outside the Second
Amendment’s scope, arms in common use today—like
magazines holding more than ten rounds—clearly don’t.
And though the Second Amendment seemingly permits
reasonable restrictions on the public carry of some
uncommon weapons, that’s not comparable to California’s
112                   DUNCAN V. BONTA


outright prohibition of the most popular magazine for self-
defense. And the lack of any historical regulations banning
the possession of a common firearm further undermines
California’s law. Finally, with no impact on armed self-
defense at all, the regulations on trap guns and gunpowder
storage are not remotely close to the burden and justification
for California’s ban. Because California failed to meet its
burden, California Penal Code § 32310 is unconstitutional.
                             III.
       THE RETURN OF INTEREST BALANCING
    The majority upholds California’s magazine ban despite
Heller, McDonald, Bruen, and Rahimi. In doing so, the
majority rejects the Supreme Court’s Second Amendment
framework and reads the Amendment as it wants. First, the
majority haphazardly establishes two Bruen tests—the so-
called more nuanced and unnuanced approaches. If that
sounds confusing, it is. In fact, it’s so confusing that the
majority largely abandons its own creation mid-opinion.
Second, rather than examine historical analogues for their
similarity with California’s regulation, the majority simply
cloaks interest balancing under the guise of “tradition.” So
in the Ninth Circuit, we’ve returned to the old days of
judicial policymaking that the Court has gone out of its way
to end.
      A. The Majority’s       Nuanced      v.    Unnuanced
         Approaches
    To begin, we can’t ignore the majority’s creation of
alternate Bruen tests—what it dubs the “more nuanced
approach” and the “straightforward,” unnuanced approach.
Maj. Op. 37, 40. Plucking a few words from Bruen, the
majority claims it may apply a “more nuanced approach”
                       DUNCAN V. BONTA                      113


anytime a regulation involves “unprecedented societal
concerns or dramatic technological changes.” Id. at 37
(quoting Bruen, 597 U.S. at 27). Although it’s unclear what
precisely the majority means by a “more nuanced approach,”
it appears to mean that we may disregard our historical
tradition of firearms regulation whenever a modern
regulation seeks to address modern problems or technology.
Id. at 37–38. Instead, whenever that is the case, the majority
calls for a more “flexible analogical approach.” Id. at 40.
This flexibility apparently means that no analysis of
historical analogues is necessary—all that’s needed is a
determination that there’s a difference between technology
or societal problems at the Founding compared to today. See
id. at 39 (analyzing how the magazine ban responds to an
“unprecedented societal concern” and the magazines here
“represent a dramatic technological change from the
weapons at the Founding” but not comparing modern
regulations to any historical analogues). So the majority’s
“more nuanced” approach is more accurately termed the
“ahistorical” approach.
    There’s much to dislike about the majority’s creation.
First, the Supreme Court has never endorsed a “more
nuanced” versus a “straightforward,” unnuanced approach.
Indeed, it would be remarkable if the Supreme Court were
forming two sets of Bruen tests without telling anyone. So
the majority’s test is just its own invention. Instead, there is
one approach: the Second Amendment’s text and historical
understanding always control.
    The majority claims to just be quoting Bruen. But take
Bruen’s comment in context: “While the historical analogies
here and in Heller are relatively simple to draw, other cases
implicating unprecedented societal concerns or dramatic
technological changes may require a more nuanced
114                    DUNCAN V. BONTA


approach.” Bruen, 597 U.S. at 27. The Court’s note about
the occasional need for a “more nuanced approach” was an
unremarkable observation that making comparisons to
proper historical analogies might be challenging at times.
Indeed, “[h]istorical analysis can be difficult; it sometimes
requires resolving threshold questions and making nuanced
judgments about which evidence to consult and how to
interpret it.” Id. at 25 (simplified). That’s especially the case
when “unprecedented societal concerns or dramatic
technological changes” may make analogical reasoning
relatively tougher. Id. at 27. Bruen and Heller’s historical
analogies, in contrast, were “relatively simple to draw” given
the extreme nature of the bans. Id. So the Court was simply
cautioning lower courts to be careful and thoughtful in
scrutinizing the government’s claim of historical analogues.
Simply, no approach that ignores history adheres to Bruen.
    But in the majority’s telling, Bruen’s discussion of a
“more nuanced” approach was the Court silently embracing
a whole new test in cases involving “unprecedented societal
concerns or dramatic technological changes.” Maj. Op. 40
(quoting Bruen, 597 U.S. at 27). And how do we know the
majority is wrong in developing its two-test regime? Just
read Rahimi. That case makes no mention of the majority’s
nuanced/unnuanced distinction. If this two-test method
were so central to Bruen, we would expect that the Court
would at least say something about it in its very first case
applying Bruen. Instead, we get zilch. Undeterred, the
majority plows ahead with its creation. Yet it has no
explanation for Rahimi’s silence on the two-tests framework.
It fails to explain whether Rahimi is a nuanced case or an
unnuanced case. It skips all of this and just moves forward
with its made-up analysis.
                      DUNCAN V. BONTA                    115


    But it gets worse. The majority also makes clear that its
“more nuanced” test is a repackaging of this circuit’s old
interest-balancing regime. The majority holds that when
governments deal with modern technology or problems, like
mass shootings, they need “even more flexib[ility]” and thus
the governments’ regulations are constitutional. Id. at 37.
All of this is just code for judicial interest balancing and
policymaking. Under this balancing regime, there’s no look
to the historical meaning of the Second Amendment—only
a review of technological or societal change and whether that
change justifies the government’s regulation. See id. at 38–
40. So, the “more nuanced” approach appears to be little
more than reinvigorated judicial means-ends scrutiny in
fancy dress. In the end, we have no doubt this “more
nuanced” approach will resemble our old “black box”
regime where “judges [simply] uphold favored laws and
strike down disfavored ones.” Duncan V, 19 F.4th at 1140
(Bumatay, J., dissenting).
    Besides flouting the Court, this two-test approach makes
no constitutional sense.       The Constitution enshrines
enduring principles. That means that the Constitution
doesn’t so easily bow to technological or societal change. In
any other context, we would scoff at the idea that the
Constitution grants broad deference to the government
simply based on the modernity of the problem. The free-
speech right didn’t change when the internet was invented.
See, e.g., Moody v. NetChoice, LLC, 

 (2024).
The Fourth Amendment right didn’t succumb to new
technology. See, e.g., Carpenter v. United States, 

 (2018). In none of these cases have courts just thrown
up their hands and declared that the government needs “more
flexibility.” So the majority’s creation is a grave mistake.
116                    DUNCAN V. BONTA


     In the end, perhaps recognizing its vast departure from
the Court’s directives, the majority retreats from its two-test
approach mid-opinion and purports to apply Bruen, as
directed by the Court. Maj. Op. 40. Even then, the majority
still gets it wrong. We turn there next.
      B. Interest Balancing As Analogical Reasoning
     By now, it should be clear what courts should do at
Bruen step two when analyzing the government’s
justification of its gun control laws. We look to whether the
modern regulation “impose[s] a comparable burden on the
right of armed self-defense and whether that burden is
comparably justified.” Bruen, 597 U.S. at 29. Our task then
is to see if historical analogues point to a limit on the Second
Amendment’s scope that justifies the regulation. In other
words, we decide whether the “how” and the “why” of the
government’s regulation and purported historical analogue
are “relevantly similar.” Id. Unfortunately, the majority
botches this analysis.
    Rather than examine historical analogues for their
similarity with California’s regulation, the majority cloaks
interest balancing under the guise of “tradition.” But it’s
easy to see the majority’s sleight-of-hand. We break it down
step-by-step.
    Step One: The majority starts off by assessing the
magnitude of California’s magazine ban’s burden on the
right of self-defense. It concludes that the burden is only
“minimal.” Maj. Op. 52 n.11; see also id. at 49
(“California’s law has a significantly smaller effect on the
speed of armed self-defense.”). The majority asserts that the
burden is small because California’s law didn’t go further.
Id. at 51 (“The law imposes no limit whatsoever on the
number of magazines[,] . . . bullets[,] . . . or . . . firearms a
                      DUNCAN V. BONTA                     117


person may own. The law also imposes no limit on the
number of rounds a person may fire or the number of
firearms a person may fire. Nor . . . does the law ban any
weapon.”). Instead, the majority says that “the law prohibits
only one very specific use of some firearms: the shooting of
an eleventh (or successive) round” without reloading and
concludes the burden minimal. Id. at 51. It then claims that
people “rarely” use magazines holding ten rounds in armed
self-defense. Id. at 52 n.11. All this ends with the majority
just declaring that these magazines are “no weapon” at all.
Id. at 55.
     The majority again falls for the fallacy that “using a
firearm” for self-defense equates to pulling the trigger and
firing every round. But the “natural meaning” of “bear
arms” is “being armed and ready for offensive or defensive
action in a case of conflict with another person.” Heller, 554
U.S. at 584 (simplified). So the right of self-defense isn’t
measured by how many bullets are expended. It’s
determined by how law-abiding citizens choose to “ready”
themselves in “case of conflict with another person.” Id.;
see also Bruen, 597 U.S. at 74–75 (Alito, J., concurring)
(retelling the stories of “potential victim[s who] escaped
death or serious injury only” because of armed self-defense
without needing to discharge a firearm or shoot the
assailant). Our criminal laws don’t require a firearm to be
discharged for it to be “used.” See, e.g., Smith v. United
States, 

 (1993). Cf. Bailey v. United States,

 (1996) (acknowledging that “use draws
meaning from its context,” such that someone can “use a gun
to protect [his] house” while “never ha[ving] to use it”
(simplified)). All that matters is that California’s total ban
on possession of magazines capable of holding more than ten
rounds “amounts to a prohibition of an entire class of ‘arms’
118                    DUNCAN V. BONTA


that is overwhelmingly chosen by American society for th[e]
lawful purpose” of self-defense. Heller, 554 U.S. at 628.
Even the majority concedes that California bans magazines
that “enhance[] . . . a person’s ability to fight or to defend”
himself. Maj. Op. 29. And it’s hard to see how the
majority’s burden analysis is any different from its step-one
conclusion that these magazines are not an “Arm[]” at all.
So the majority just confuses the step one and step two
inquiry.
    In any case, we proceed with the majority’s interest
balancing.
    Step Two: Having arrived at its stylized burden, the
majority moves on to analyze historical regulations’
purported justifications. Misreading history and attempting
to extract the broadest of generalities, the majority
manufactures a “tradition of regulating a particular,
especially dangerous use of a weapon, once that use becomes
a specific threat to innocent persons.” Id. at 56, see also id.
at 41 (“Beginning before the Founding and continuing
throughout the Nation’s history, legislatures have enacted
laws to protect innocent persons from especially dangerous
uses of weapons once those perils have become clear.”). As
explained above, no historical analogue supports this made-
up tradition. And in reality, the majority just seeks to
recognize a broad “public safety” justification for
government regulation. Under the majority’s view, this
justification gives States the ability to regulate any arms for
public safety. Such a justification swallows the entire
Second Amendment right.
     Step Three: The majority then makes a factual leap—
finding that magazines holding more than ten rounds fit the
bill of an “especially dangerous” weapon. In the majority’s
                       DUNCAN V. BONTA                     119


view, “[l]arge-capacity magazines exacerbate the harm
caused by mass shootings, and limiting magazine capacity
thus prevents or mitigates the harm caused by mass
shootings.” Id. at 48. Of course, the majority cites no facts
to support this. Even more, it doesn’t explain how these
magazines are “especially dangerous” firearms or under
what baseline it makes this comparison. How are we to
decide when a firearm is just “dangerous” versus “especially
dangerous”? Only the majority knows.
    Step Four: The last step is the majority’s comparison of
the burden of the magazine ban to the supposed justification
for outlawing “especially dangerous” weapons. In the
majority’s view, because the “same justification underpins
California’s restriction on magazine capacity” as historical
laws and because California’s ban imposes “less of a
burden” on armed self-defense than some historical laws, it
is constitutional. Id. at 47, 55–56. In other words, it takes a
broad justification (the “why”) and compares it with a
minimal burden (the “how”) and finds a match.
    So rather than compare the justifications and burdens to
“relevantly similar” analogues, the majority just looks to the
fit between a generalized “why’” and an in-the-ballpark
“how.” But this crosses wires. We are not supposed to
compare the “how” to the “why”; we’re supposed to
compare the “how and why” of modern regulations to the
“how and why” of analogous historical regulations. If the
historical and modern regulations share a common “how and
why,” then this may reveal that the regulation is outside of
the scope of the Second Amendment. Put another way, we
must see whether California’s magazine ban “works in the
same way and does so for the same reasons” as historical
regulations. Rahimi, 602 U.S. at 711 (Gorsuch, J.,
concurring). Instead, the majority merely points to some
120                   DUNCAN V. BONTA


historical “whys” and some historical “hows” and calls it a
day. Although they try to disclaim it now, make no
mistake—this is what the majority has been doing and
continues to do.
    Take the majority’s analysis of Bowie knife and
slungshot regulations. The majority claims the regulation of
both weapons supports its supposed tradition of regulating
“especially dangerous” weapons. But it also acknowledges
that the only historical burden on those weapons was to
“ban[] their carry outside the home.” Maj. Op. 45. So even
if the majority were right, the justification of regulating
“especially dangerous” weapons only leads to the
prohibition of carrying the weapons outside the home—not
outright possession bans as California enacts.
     If comparing the “how” to the “why” of a regulation
sounds familiar, it is. It’s interest balancing 101—this time
masquerading as respect for the Second Amendment’s
historical scope. The majority’s analysis bears all the
hallmarks of judicial means-ends balancing—determining
first whether California’s interest is compelling, then
assessing the severity of the burden, and then evaluating
whether California’s means fit its end. Look at the
majority’s language pre-Bruen and post-Bruen and notice
how little has changed (even after the majority attempts to
mask its defiance):
                     DUNCAN V. BONTA                    121


   MAJORITY PRE-BRUEN             MAJORITY POST-BRUEN
“[L]arge-capacity              “Mass      shootings   are
magazines         tragically   devastating for the entire
exacerbate the harm            community, and large-
caused      by        mass     capacity         magazines
shootings.”                    exacerbate the harm.”
 Duncan, 19 F.4th at 1109                     Maj. Op. 47
“California’s ban on large- “California’s law imposes
capacity        magazines only a minimal burden on the
imposes only a minimal right of armed self-defense.”
burden on the exercise of                Maj. Op. 52 n.11
the Second Amendment
right.”
 Duncan, 19 F.4th at 1104
“[W]e conclude that       “Its prohibition on a
California’s ban is a     weapon’s component that
reasonable fit, even if an serves the sole function of
imperfect one, for its    enabling a specific, and
compelling      goal    ofespecially dangerous, use of
reducing the number of    a firearm fits neatly within
deaths and injuries causedthe tradition” of banning
by mass shootings.”       especially        dangerous
 Duncan, 19 F.4th at 1110 weapons.
                                       Maj. Op. 53–54
“California’s ban on large- “California’s        modern
capacity magazines is a law[’s] . . . justification   for
reasonable fit for the burdening the right to armed
                            self-defense” [fits the need]
122                    DUNCAN V. BONTA


 compelling      goal     of to protect innocent persons
 reducing gun violence.”     from      infrequent    but
   Duncan, 19 F.4th at 1111 devastating harm.”
                                                 Maj. Op. 47

    Bruen did two things: (1) it ended judicial interest
balancing and (2) it provided a new framework for
considering Second Amendment challenges. Despite this
revolutionary change, things remain the same at the Ninth
Circuit. Faithfully applying Bruen requires a course
correction that the majority refuses to take. Instead, the
majority just declares it knows better and charts its own path.
But that disrespects the Supreme Court and the rule of law.
                             IV.
                      CONCLUSION
    At each step of this case, the majority has made clear its
disdain for the Supreme Court’s Heller-McDonald-Bruen-
Rahimi jurisprudence. But our job is to follow even if we
disagree. Because California’s magazine ban violates the
Second Amendment’s text, history, and tradition, we
respectfully dissent.
                      DUNCAN V. BONTA                     123


VANDYKE, Circuit Judge, dissenting:

    Three years ago, the Supreme Court vacated our court’s
opinion in this very case, presumably because we tried the
same tack that Bruen rejected in no uncertain terms:
engaging in interest balancing after assuming that an activity
falls within the scope of the Second Amendment. In other
words, our court’s reliance on interest balancing (like the
Second Circuit’s decision in Bruen) took “one step too
many.” N.Y. State Rifle & Pistol Ass’n v. Bruen, 

 (2022). Because, as the Supreme Court made clear
enough in District of Columbia v. Heller, the Second
Amendment is itself “the very product of an interest
balancing by the people,” it is not our role to “conduct [it]
for them anew.” 

 (2008).
    Notwithstanding these repeated directives to stop,
today’s decision doubles down on this court’s prior practice
of balancing away the rights of law-abiding citizens to bear
arms in self-defense—only this time under another name.
Rather than balancing after concluding that the original
understanding of the Second Amendment protects an
individual’s conduct, the majority now merges its balancing
into its determination of whether the Second Amendment
protects an individual’s conduct at all. This reinforces why
interest balancing must have no place in applying the Second
Amendment. See Duncan v. Bonta (Duncan V), 

, 1159–60 (9th Cir. 2021) (en banc) (VanDyke, J.,
dissenting), cert. granted, judgment vacated, 

(2022), vacated & remanded, 

 (9th Cir. 2022).
    I wholeheartedly agree with Judge Bumatay’s excellent
dissent, which thoroughly demonstrates the correct approach
under the Second Amendment following Bruen. I write
separately to further highlight some serious flaws in the
124                    DUNCAN V. BONTA


majority’s analysis. If some of what you read below sounds
familiar, it is because, consistent with the majority’s reuse of
balancing by another name, many of the flaws I identify are
barely disguised retreads of those I pointed out in our last
iteration of this case. 

 at 1160–70. Notwithstanding
Bruen, very little has changed about the Second Amendment
out here in the Ninth Circuit.
                               I.
     The majority begins with Bruen’s cue to first determine
whether “the Second Amendment’s plain text covers an
individual’s conduct.” 

. One might expect
this to be a mechanical or routine part of the analysis,
especially considering the Supreme Court’s emphasis that
there is only one step in assessing a Second Amendment
claim. 

. But many lower courts, like ours, have
instead taken Bruen’s guidance to mean there is an extensive
first-step, arm-or-not inquiry. According to the majority,
California is correct that a larger capacity magazine is not an
“arm” within the meaning of the Second Amendment
because it is “an accessory, or accoutrement, not an ‘Arm’
in itself.” As a result, the majority concludes the
Constitution does not “presumptively protect[]” it.
    But whether a firearm component is an inherent and
“necessary” part of the arm itself, or instead merely an
“optional” and unnecessary accessory to the arm, is a
hopelessly indeterminable and inadministrable distinction.
As is true for almost any type of object—from cars to
computers to sewing machines to software—there is no
Platonic ideal of a firearm from which such distinctions
between “inherent” and “optional” parts can be objectively
derived. Yet the majority relies on its invented “arms–
accessory” distinction as an on/off switch for fundamental
                      DUNCAN V. BONTA                     125


constitutional protections. Because that distinction has no
basis in reason or reality, what this new test is really cover
for is the majority’s ipse dixit. A higher capacity magazine
is an accessory, and thus unprotected by the Second
Amendment, because the majority says so. And a lower
capacity magazine (as yet undefined) is a “necessary” part
of the arm, and thus protected, again because the majority
says so. This is a terribly unprincipled way to analyze
constitutional rights.
    Initially, I planned to explain my reasons for dissenting
on this conceptual point through usual judicial means alone:
describing in writing some real-world illustrations to explain
how the majority’s supposed “arms–accessory” distinction
collapses. But at argument it became clear to me that a visual
illustration would greatly aid my colleagues and the parties
in better grasping how this rather obvious conceptual
problem specifically applies to firearms. So instead of
straining to use written words to explain the many different
parts of a gun and how each part could easily be deemed an
“accessory” under the majority’s vacuous test, I have
decided to deliver part of my dissent in this case orally—via
video—under the established wisdom that showing is
sometimes more effective than telling. Please click the link
below and enjoy the presentation:
  https://www.ca9.uscourts.gov/media/23-55805/opinion
    As I hope the video portion of this dissent helpfully
illustrates, an “arm”—just like most other categories of
objects known to the human experience—is a broad
conceptual term covering an almost limitless variety of
configurations within that category. See Bruen, 

 (explaining that the term “extends, prima facie, to all
instruments that constitute bearable arms” (emphasis
126                    DUNCAN V. BONTA


added)). The majority does not and cannot dispute that. It
acknowledges that “the meaning of ‘Arms’ … broadly
includes nearly all weapons used for armed self-defense.”
But the majority nonetheless concludes that in its view some
parts of a firearm are “necessary to the operation of a
weapon” and thus protected by the Second Amendment,
while other parts are not necessary and therefore not
protected “arms.” The majority then purports to apply its
misguided new test to decide that higher capacity magazines
are not arms, while lower capacity magazines are.
    The majority’s new constitutional test fails at the most
basic level possible—the conceptual level. Its failure is not
even related to anything particularly unique to firearms. The
inherent indeterminability of categorizing constituent parts
of a class of objects as either belonging to the class itself or,
instead, merely functioning as “unnecessary accessories” to
that class should be self-evident for almost everything from
cars (doors?) to cellphones (cameras?) to cereal
(marshmallows?). Firearms are of course no different. The
only difference is that the majority’s test as applied to
firearms is not just philosophically goofy, but it also has the
very real and troubling result of denying Americans’
constitutional rights.
    It is so easy to demonstrate the conceptual failings of the
majority’s new test that even a caveman with just a video
recorder and a firearm could do it. For example, while the
majority concedes that “triggers” are firearm components
due at least some Second Amendment protection, the
majority’s misguided test cannot support that conclusion.
Even something as essential to the firearm as a
manufacturer-issued trigger could be considered an
unprotected “accessory” under the majority’s view because
that particular trigger is not essential to the function of the
                      DUNCAN V. BONTA                     127


firearm, as it could be swapped out for one with less
effective, and therefore less “dangerous,” attributes.
    The problem with the majority’s misguided test is no
different with respect to larger capacity magazines. My
colleagues in the majority reason that “a magazine is an
integral part” to the operation of a semi-automatic gun and
therefore “that the Second Amendment’s text encompasses
a right to possess a magazine.” I agree. But the majority
also contends that a “large-capacity” magazine “is not
necessary to operate any firearm” and is therefore not an arm
or a protected component. California defines a large-
capacity magazine as any magazine holding more than ten
rounds. But why stop there? Under the majority’s rationale,
any magazine that holds more than one round is not
“necessary” for the function of the weapon. So presumably
California could also ban magazines holding five rounds.
Maybe even two.
    And why stop at magazines? According to the majority,
because “firearms operate as intended without a large-
capacity magazine,” and a large-capacity magazine is not
“necessary to the ordinary functioning of a firearm,”
large-capacity magazines are not protected under the Second
Amendment. But under that logic, basically every part of a
firearm is an “optional component” because each could be
replaced with a less effective (aka, less “dangerous”) version
of that part and the firearm would still “operate” in some
sense.
    Nor is it at all clear what the majority means by “as
intended” and “ordinary functioning.”         Technically
speaking, I suppose that would mean a grip or a sighting
system is not a protected component of a firearm because
those pieces are “optional components” not strictly
128                    DUNCAN V. BONTA


necessary to make the gun fire a round. Some handguns
come without any sights at all. Those guns are obviously
difficult to aim accurately. So does that mean California
could ban all grips and sights under the majority’s test?
After all, just as a magazine is only “a box that, by itself, is
harmless,” a grip could be characterized as just a piece of
polymer, a barrel as just a steel tube, and a bullet as just a
small hunk of metal. Each one of those pieces, just like
every other individual part of a firearm, “is benign” and
“useless in combat for either offense or defense” without the
rest of the firearm.
    More basically, what do my amateur gunsmithing
colleagues mean by “operate as intended?” Take a red dot
optic. A firearm equipped with a red dot optic is “intended”
to be operated more quickly and accurately than a firearm
without one. So I suppose you could say the red dot optic is
“necessary” to make the red-dot-optic-equipped firearm
“operate as intended.” But of course, like many parts of
modern firearms, it is not necessary at all if “operate as
intended” means only the bare minimum functionality
needed to send a bullet downrange. Is a red dot optic an
unprotected accessory or a protected component under the
majority’s test?
    As another example, most modern handguns have an
automatic cycling mechanism that, upon firing, expels the
spent cartridge, loads a new round, and resets the trigger.
But plenty of firearms do not have an automatic cycling
mechanism.        The automatic cycling mechanism is
“necessary” to make a semi-automatic firearm “operate as
intended,” but it is not necessary to make, say, a revolver or
a bolt-action or a single-shot break-action firearm operate.
Could California ban all semi-automatic handguns by
applying the majority’s logic that, because the automatic
                            DUNCAN V. BONTA                             129


cycling mechanism is not required to make a handgun work,
it’s simply not protected by the Second Amendment? 1
    The majority’s test produces head-scratching results. On
the one hand, the majority gives lip service to the fact that
“[t]he meaning of ‘Arms’ … broadly includes nearly all
weapons used for armed self-defense.” But on the other, its
reasoning inevitably means that only the most dumbed-down
or basic version of any component part of a gun is
protected—and many parts of a gun are entirely unprotected
if they aren’t strictly necessary to make a gun go bang.
Similarly, the majority acknowledges that the Second
Amendment “must carry an implicit, corollary right to bear
the components or accessories necessary for the ordinary
functioning of a firearm.” But the obvious result of the
majority’s test is that almost all of the component parts of a
firearm would fall completely outside the Second
Amendment because, in theory, any particular part could be
replaced with a dumbed-down version of the same part. In
another place, the majority suggests that “any accessory”
performs a specific function that “enhance[s] … a person’s

1
  The majority’s historical examples fail to shed light on the bounds of
its test. The majority explains that, historically, “accoutrements” like
“flint, scabbards, holsters, and ammunition containers” were “distinct
from ‘arms.’” But under the “necessary to the ordinary functioning” test
posited by the majority, one would have assumed flint would clearly be
covered as a component part of a firearm. Flint is integral to the actual
firing of a flintlock firearm. Akin to how a modern-day striker or firing
pin ignites the primer in a cartridge, starting the chain reaction that fires
a bullet, flint creates a spark that ignites gunpowder in a flashpan that
causes the gun’s discharge. Granted, flint is a material that degrades
more quickly than the material comprising a modern firing pin and
therefore must be replaced with some frequency, but it is absolutely a
required part to make a flintlock firearm “operate as intended.” A
flintlock will not work without flint.
130                   DUNCAN V. BONTA


ability to fight or to defend.” So the majority seems to
acknowledge that its test devolves to exclude anything that
enhances a firearm’s operation—or, put more bluntly,
anything that works too well. In the end, the majority’s test
boils down to something like this: the Second Amendment
presumptively protects only the jankiest version of a firearm
and a little bit of ammunition (2.2 rounds?). Sound familiar?
See Duncan V, 

 (VanDyke, J., dissenting).
     The only way the majority can classify a large-capacity
magazine as “an optional accessory” is if it has some idea of
what is (and is not) “optional.” Put differently, the majority
must have at least some idea of what a “standard” firearm is.
The majority’s logic is premised on its assumption that there
is some Platonic ideal of a firearm, which I guess makes
sense if you think judges are the Platonic Guardians of the
Second Amendment. That’s a nice job if you can get it, but
it should be clear enough by now that many judges (and gun-
banning governments) know next to nothing about how guns
actually work, which perhaps explains why they would
invent such an obviously inadministrable test for guns, but
never for any other constitutional right.
    Ultimately, just as with televisions and sewing machines,
there is no such thing as a stock-part basic firearm,
unadorned and without any “accessories,” that constitutes
the only “arm” protected under the Second Amendment.
There are many parts that constitute the arm, most of which
usually can be swapped out to emphasize and improve
certain functions over others. Consider, for example,
heavier grips that make the gun steadier when shooting
versus lighter ones that are easier to carry and conceal. Just
as the First Amendment doesn’t apply only to “necessary”
or “essential” speech, the Second Amendment cannot apply
only to firearms containing just those parts that a state like
                          DUNCAN V. BONTA                            131


California deems essential and necessary. Instead, what
constitutes the “arm” includes every functional component
and not only the most downgraded version of a “necessary”
component. Cf. Jackson v. City & Cnty. of San Francisco,

, 967–68 (9th Cir. 2014) (holding that hollow-
point ammunition is covered by the Second Amendment
because of the “corresponding right to obtain the bullets
necessary to use firearms” (cleaned up)); Fyock v.
Sunnyvale, 

 (9th Cir. 2015) (recognizing
that this same principle applies to magazines).
                                  II.
    The majority’s analytical flaws do not end at the first step
of its analysis.       Despite initially (and incorrectly)
determining that large-capacity magazines are not part of the
arms covered by the Second Amendment at all, the majority
proceeds to assess whether a ban on large-capacity
magazines is consistent with history and tradition. Judge
Bumatay aptly explains how the majority’s analysis errs as a
historical matter. I will elaborate on just a few points.
   The majority explains that for “cases implicating
unprecedented societal concerns or dramatic technological
changes,” we should apply “a more nuanced approach.” 2 It

2
 Here, the majority determines that such an approach is justified because
“[l]arge capacity magazines, when attached to a semi-automatic firearm,
… represent a dramatic technological change” because they “fire with an
accuracy, speed, and capacity that differ completely from the accuracy,
speed, and capacity of firearms from earlier generations.” The majority
seems to recognize the truth that most of the “dramatic technological”
jump since the Founding is attributable to the automatic cycling
mechanism—not the large-capacity magazines at issue here.
Presumably then, because that mechanism accounts for most of the
“dramatic” change making modern firearms “especially dangerous”
compared to the muzzleloaders of our forefathers, the unstated
132                       DUNCAN V. BONTA


is true that the Supreme Court explained that some societal
changes would be so unprecedented—and some
technological changes so great—that historical regulations
would not have contemplated them. Bruen, 

.
In those cases, courts should “reason[] by analogy.” 

. But rather than look for close analogues that “impose a
comparable burden on the right of armed self-defense” that
“is comparably justified,” 

, the majority warms up
by opining that analogues should be “flexible.” What the
majority’s new “flexible” and “nuanced” approach devolves
into is that the government need only show the sloppiest of
a fit between the historical example and the modern
regulation.
    To show you what I mean, consider the majority’s use of
gunpowder storage laws as an example of a historical
regulation analogous to California’s ban on magazines
holding more than ten rounds. Under Bruen, we must look
to “why” gunpowder storage laws existed and “how” those
regulations burdened the Second Amendment by requiring
gunpowder to be stored in a special container or place in the
home.
    Start with the “why.” As the majority acknowledges,
those laws existed “to prevent … fires and explosions from
the storage of gunpowder,” or by “prohibiting what had
proved to be an especially dangerous” practice. Heller itself
summarized these storage laws in a similar way. 

 (distinguishing gunpowder storage laws because they
“did not clearly prohibit loaded weapons, but required only



conclusion that follows from the majority’s misguided analysis is that a
state could ban semi-automatic handguns altogether.
                          DUNCAN V. BONTA                            133


that excess gunpowder be kept in a special container or on
the top floor of the home”).
    So far so good. But how do those laws look anything
like the magazine ban at issue here? If that leap confuses
you, you’re in good company. To get from gunpowder
storage laws to bans on magazines with more than ten
rounds, the majority must summarize the “why” as “to
prevent a specific, infrequent type of harm to innocent
persons,” or as they further summarize it, to stop “an
especially dangerous use of firearms.” Turning to the next
step, the majority characterizes the “how” as completely
“prohibiting” certain methods of storage. So the majority
generalizes the history-and-tradition test—first explicated in
Bruen and then expanded upon in United States v. Rahimi,

 (2024)—to the level of “especially dangerous”
and posits that the government can completely ban anything
that fits that definition. It is hard to imagine a degree of fit
much sloppier than that. 3
     By taking any historical example that completely bans a
specific activity and raising the level of generality for the
“why” to something akin to mere “dangerous[ness],” it is
hard to see how any gun regulation wouldn’t pass muster,
because governments have been banning “dangerous” stuff
and activities since time immemorial. In fact, I would
venture to guess that even the regulations that failed in
Heller or Bruen would survive such trifling scrutiny. After
all, (1) lots of historical laws have prohibited dangerous
things, and (2) even the jankiest firearm in the hands of the
wrong person is “especially dangerous.” So what stops the

3
  I use this one example to illustrate my point, but the point stands for
the other historical analogues the majority suggests, as discussed in
Judge Bumatay’s dissent.
134                    DUNCAN V. BONTA


government from banning the possession of all firearms
under the majority’s loose test?
    But that’s not the only way the majority overhauls the
Supreme Court’s test. The majority goes on to candidly
acknowledge that, in its view, “every Second Amendment
case involves dramatic technological changes.” One can
imagine now the reasoning our court will employ in the
future to substantiate this pronouncement. Cases like
Rahimi—with a focus on domestic violence—will come to
stand for the proposition that all modern societal ills even
conceivably related to firearms are “dramatic [societal]
changes” justifying the majority’s sloppier, “more nuanced
approach.” And any appreciable advance in firearms
technology—whether that is the automatic cycling
mechanism, higher ammunition capacity, better optics, an
improved barrel, etc.—will come to represent a “dramatic
technological change” that the Founders could not possibly
have comprehended.
    The inevitable consequence—and presumably the
intended effect—of such a rule is that circumstances will
always be different enough to justify the “more nuanced
approach.” And the “more nuanced approach” will always
justify ill-fitting comparators. What is the end effect of this
scheme? It essentially writes Bruen out of the United States
Reports—at least out here in the Ninth Circuit.
Notwithstanding Bruen’s clear command that the
government will be held to its burden of showing a
“distinctly similar historical regulation” to succeed in a
Second Amendment case, 

 (emphasis
added), the judges of this circuit will always find some
reason or another to excuse the government from meeting
that burden. E.g., United States v. Perez-Garcia, 115 F.4th
                      DUNCAN V. BONTA                    135


1002, 1011 (9th Cir. 2024) (VanDyke, J., dissenting from the
denial of rehearing en banc).
    To summarize, the majority’s test boils down to whether
any new gun regulation was passed to deal with situations
that are “especially dangerous.”          Why “especially
dangerous” as opposed to just dangerous? Perhaps because
the majority implicitly recognizes that merely “dangerous”
would be too obviously defiant. Dangerousness itself is
clearly inherent in the definition of a weapon: “An
instrument used or designed to be used to injure or kill
someone.” Weapon, BLACK’S LAW DICTIONARY (12th ed.
2024); see also Commonwealth v. Canjura, 

,
221–22 (Mass. 2024) (“In the most basic sense, all weapons
are ‘dangerous’ because they are designed for the purpose of
bodily assault or defense.”). And because the very purpose
of a weapon is to be “dangerous,” the more dangerous a
weapon is—whether because of concealability, stopping
power, ease of use, rate of fire, or any number of other
considerations—the better it is at doing what it was designed
to do. A rule that allows a ban on all “dangerous” weapons
could thus effectively be a ban on all weapons. Full stop.
The majority—and California—know they cannot create a
test that bans any firearm that anyone could perceive as
“dangerous” because every firearm has the capacity to cause
serious harm if used improperly or placed in the wrong
hands. So instead, California points to its conclusion that
large-capacity magazines are “uniquely dangerous,” and the
majority finds a historical underpinning for a ban on all
weapons that are “especially dangerous.”
    Of course, the test for what qualifies as “especially
dangerous” looks quite a lot like the majority’s interest-
balancing test from the days of Duncan’s past. To begin, the
majority evaluates the “how” by explaining that California’s
136                   DUNCAN V. BONTA


law imposes only a “minimal burden” on a plaintiff
interested in exercising his Second Amendment right, which
sounds a lot like a cut-and-paste of the first step of
intermediate scrutiny. Compare Duncan V, 

 (“California’s ban on large-capacity magazines
imposes only a minimal burden on the exercise of the Second
Amendment right.”), with the majority here (“California’s
law imposes only a minimal burden on the right of armed
self-defense.”). According to the majority, the burden on
such an individual is only minimal because the law “imposes
no limit whatsoever on the number of magazines a person
may own, the number of bullets a person may own, … the
number of firearms a person may own, … the number of
rounds a person may fire[,] or the number of firearms a
person may fire.” Judge Graber, in both the majority opinion
and her concurrence, made that point last time too. See
Duncan V, 

; 

 (Graber, J.,
concurring) (“[A]lternatives nevertheless remain: the
shooter may carry more than one firearm, more than one
magazine, or extra bullets for reloading the magazine.”).
And I already pointed out how that is unrealistic. 

(VanDyke, J., dissenting).         The majority also again
emphasizes that firing more than ten rounds “occurs only
rarely, if ever, in armed self-defense.” My colleagues made
this same argument last time, and I explained then why it
doesn’t hold water. 

. Nevertheless, as before, the
majority concludes that the large-capacity magazine ban is
minimally burdensome because it only “prohibit[s] one
specific and rare use of semi-automatic firearms.” Compare
with 

 (majority op.) (“The ban on large-capacity
magazines has the sole practical effect of requiring shooters
to pause for a few seconds after firing ten bullets.”).
                      DUNCAN V. BONTA                     137


    Next, the majority goes on to evaluate the “why,”
determining that California’s law is similar to its historical
analogues because “[m]ass shootings are devastating for the
entire community, and large-capacity magazines exacerbate
the harm.” This again looks quite a lot like the discredited
intermediate scrutiny test that the majority applied the last
time around. 

 at 1109–11. Because California’s law seeks
“to prevent or mitigate … devastating harm … to innocent
persons” due to “especially dangerous uses of weapons,”
California’s law must be justified. See 

(“California’s law aims to reduce gun violence primarily by
reducing the harm caused by mass shootings.”).
    Is it just me, or do we seem to be right back where we
were before Bruen? Except somehow worse. In important
ways, the majority’s lax historical balancing test is even
easier for the government to satisfy than intermediate
scrutiny. Here, the majority discusses the burden on an
individual’s right to self-defense, just like it did in Duncan
V. But if the majority can already point to a historical
analogue of a complete ban on a weapon, why does it need
to show a minimal burden at all? Really, so long as it has a
matching “why”—and there always will be a matching
“why” because the inherently dangerous nature of firearms
will always match the majority’s permissive “especially
dangerous” level of generality—any new law could similarly
burden the individual’s right to self-defense in the same way
as any ban at the Founding. Cf. Canjura, 240 N.E.3d at 221–
22 (recognizing that all weapons are inherently dangerous).
   More glaringly, when considering whether the risk of
harm is justified, the majority weighs everything in favor of
the government and ignores the always-corresponding
burden that the ban imposes on law-abiding citizens. Like
every part of a firearm, large-capacity magazines are of
138                   DUNCAN V. BONTA


course “especially dangerous” in the hands of a criminal. So
is having a semi-automatic instead of a single-shot handgun.
And so is having good sights that help the criminal hit what
he’s aiming at.
    On the other hand, not having good sights decreases the
usefulness for law-abiding citizens. And so does having a
lower capacity magazine and being forced to reload when
put in a lawful self-defense situation. Take the majority’s
thrice-repeated line: “The short pauses when a shooter must
reload a firearm afford intended victims and law
enforcement officers a precious opportunity to flee, take
cover, and fight back.” But what of armed victims
attempting to defend themselves and others? They too must
pause to reload, and their pauses give assailants time to get
off more shots. Not to mention the greater potential for
malfunction with every magazine swap. And that is only if
the victim happens to be carrying an extra magazine in a
place where she can quickly get to it. Pauses in shooting
don’t just mean a chance for victims to take cover. Pauses
in shooting while trying to reload also mean a chance for
victims to be overwhelmed by criminal assailants. It always
works both ways.
    Yet the majority sees only a one-way street, claiming that
the need to reload in a self-defense situation “seldom”
occurs.      We’ve been down this road before, too.
Statistically, mass shootings almost never occur either.
Duncan V, 

 (VanDyke, J., dissenting). But
for the majority, extremely rare criminal acts count against
the Second Amendment while similarly rare self-defense
needs are irrelevant.
    The majority’s assumption that the need to reload in a
self-defense situation “almost never” happens in real life
                           DUNCAN V. BONTA                            139


may not be as justified as it thinks, though, and becomes
even less so in a modern society increasingly plagued by
unchecked group violence. There is at least one disturbing
example from right here in the Ninth Circuit—indeed, not
far from where we heard oral argument in this case. In
October 2021, retired police captain Ersie Joyner was
pumping gas in Oakland when a group of assailants
attempted to rob him at gunpoint in broad daylight. 4 The
assailants pointed their guns and repeatedly told each other
to shoot Joyner, even as he complied with all their demands. 5
Joyner was carrying a Glock 43, and eventually made the
choice to defend himself. He fired at the assailants, and they
returned fire. Joyner fired ten times, emptying his magazine.
He can be seen on the gas station’s security footage having
to then take cover and pretend to shoot back while the
assailants continued to shoot him at close range before
finally driving away. Remarkably, Joyner survived. But he
was shot multiple times before the assailants fled, leaving
twenty-two bullet holes in his body.
    Again, that is just one anecdote, and I don’t dispute that
these situations are uncommon. 6 But as I explained in my

4
  See KTVU Newsroom, Retired Oakland police captain wounded, 1
other killed during gas station gun battle, KTVU Fox 2 (Oct. 22, 2021,
5:30 AM), https://perma.cc/8E35-Z8SB.
5
  See Lisa Fernandez & Andre Senior, Ersie Joyner ‘humbled and
humanized’ after surviving 22 bullet wounds in Oakland shootout,
KTVU Fox 2 (Feb. 26, 2022, 6:26 AM), https://perma.cc/54ZA-BVF7.
6
  Indeed, as I’ve emphasized before, all self-defense uses of firearms are
relatively uncommon. Duncan V, 

 (VanDyke, J.,
dissenting) (noting “the practical infrequency of any particular person’s
need to actually defend herself with a gun”). So the uncommonness of
the need to use a firearm for self-defense cannot be a reason to deny the
Second Amendment’s protections.
140                   DUNCAN V. BONTA


previous Duncan en banc dissent, so are all instances where
individuals need to actually fire a gun to defend
themselves—including against mass shootings, which form
the majority’s and California’s shared rationale for these
bans. 

 As I stated then, the standard cannot be based on
the “practical infrequency of any particular person’s need to
actually defend herself with a gun,” or on the practical
infrequency of her need to use multiple rounds to do so. 

We shouldn’t be balancing the Second Amendment at all.
But if the majority can’t help itself, it should at least stop
loading the scales. Watering down the history-and-tradition
test the way that the majority does here creates real
consequences for real people exercising their Second
Amendment rights.
                             III.
    Finally, I must respond to Judge Berzon’s concurrence
attacking at some length the video portion of this dissent as
“wildly improper.” She levels three criticisms: (1) that our
court’s rules don’t allow for part of my dissent to be
presented in video format, (2) that I have “egregiously …
appointed [my]self as an expert witness in this case,” and
(3) that my video improperly introduces “facts outside the
record.” I’ll respond to each of these accusations in turn.
     Demonstrating the majority’s consummate textualist
bona fides, Judge Berzon’s first criticism starts and ends
with the text of our court’s General Orders: “[T]he
determination of each appeal … shall be evidenced by a
written disposition.” 9th Cir. Gen. Ord. 4.5(a) (emphasis
added). Judge Berzon emphasizes “written,” and I’m never
one to dispute that words can be “a real workhorse when
italicized,” particularly in Second Amendment cases.
McDougall v. Cnty. of Ventura, 

, 1122 n.5 (9th
                       DUNCAN V. BONTA                     141


Cir. 2022) (VanDyke, J., concurring). But emphasizing one
word doesn’t license us to ignore the rest of the text. General
Order 4.5(a) doesn’t even say that “the determination of each
appeal” shall be “in writing,” much less that it shall be
entirely or solely in writing. It says only that the
“determination of each appeal … shall be evidenced by a
written disposition.” 9th Cir. Gen. Ord. 4.5(a) (different
emphasis added). It should be self-evident that if the rule
requires only that “the determination … be evidenced by a
written disposition” then it doesn’t require that it be “a
written disposition”—just evidenced by one. In other words,
our court can’t just issue an oral ruling from the bench
disposing of a case that is never memorialized—i.e.,
“evidenced”—in writing. The administrative need for such
a rule is obvious enough.
    My dissent clearly is “evidenced by” a written
disposition. Much of the dissent is actually written, and this
written portion evidences (i.e., refers to) the oral portion.
And even if the rule required that the disposition itself be
written, that too would be satisfied by my dissent—which
again, is written in part. Indeed, only if the rule
unambiguously required that the “determination of each
appeal” be only in writing would Judge Berzon’s criticism
have any merit. But aside from running squarely into the
phrase “evidenced by,” such an extreme reading of General
Order 4.5(a) would also be inconsistent with our court’s
established practice. We have long included links to videos
in our court’s opinions, as well as pictures, timelines, and
diagrams. Nobody thought that was a problem until now,
and Judge Berzon even defends that practice in her
concurrence. In short, Judge Berzon’s overreading of
General Order 4.5(a) is just that—an overreading. Like the
majority’s invention of its facile arms–accessory test, the
142                    DUNCAN V. BONTA


“textual” argument against my video dissent seems driven
more by a desire for a certain result than anything in the text
or reason itself.
    Most of Judge Berzon’s withering fire, however, is
directed at the perception that I’ve made myself a factual
expert in this case. First, I would be remiss if I didn’t say
thank you. But as much as I may be flattered, I think the
accusation misses the mark—indeed, I think my colleagues
aren’t even aiming at the right target. My criticism of the
majority’s reliance on the arms–accessory distinction to
decide this constitutional case is fundamentally a conceptual
one, not a factual one. As already noted, it has nothing to do
with any unique characteristics of firearms per se, but is
rather an intrinsic conceptual shortcoming with the
majority’s ill-advised approach that makes a fundamental
right turn on whether some object has certain “inherent”
qualities or is instead an “unnecessary” add-on to the
Platonic ideal of some category. Illustrating that conceptual
shortcoming with the majority’s approach doesn’t
necessarily require any factual “expertise” about firearms. It
just requires a certain level of logical and analytical rigor
combined with good judgment in not creating clearly
inadministrable constitutional tests—precisely the type of
legal expertise we expect in our jurists. So again, thank you.
    Judge Berzon’s related accusation that the video portion
of my dissent introduces “facts outside the record” is
misguided for the same reason. Again, the fundamental
purpose of the video is to convey a conceptual point, not any
particular disputable facts about guns. The same conceptual
point could have been illustrated in video form using
essentially any tangible object. I could, for example, have
referred to the variety in foot types or bobbin styles on a
sewing machine to illustrate the inherent indeterminability
                       DUNCAN V. BONTA                     143


in making the majority’s inappropriate legal test turn on
whether part of an object is an “integral part” or merely an
“accessory.” Or I could have stood by a car and talked about
tires and windshield wipers. The factual specifics of how
any particular parts work on any particular object is not what
is important—it’s the conceptual point that matters.
    But this is a case about guns, after all, and the
Constitution protects the right to bear arms, not cars or
sewing machines. So it seems appropriate to use firearms to
illustrate my conceptual criticism. The majority’s odd
obsession with the factual content of the video—while
intentionally blinding itself to my conceptual point—
appears to be a bad case of intentionally avoiding the forest
by fixating on the trees.
    There are several strong indicators that Judge Berzon’s
and the majority’s “facts outside the record” complaint about
my video dissent is just a manufactured concern. First, if
you have watched the video portion of my dissent and also
read up to this point you are no doubt aware that the written
portion of my dissent makes the same conceptual argument
as the video: it talks about the same firearms parts except in
written form. Yet the majority has never complained that the
written portion of my dissent “includes facts outside the
record.” The difference between the two formats (written
and video) is not the supposed factual content, but rather that
for some reason the video format is harder to ignore. So the
majority has fabricated a sham procedural reason to justify
ignoring it anyway.
    The majority’s newfound punctiliousness for
scrupulously avoiding any reference to facts outside the
record would perhaps ring truer if it was evenly applied in
Second Amendment cases. Only a few years ago, the same
144                   DUNCAN V. BONTA


judge who has authored the majority opinion in this case
authored an opinion in another case denying Second
Amendment rights—and relied extensively on extra-record
facts in doing so. See Mai v. United States, 

,
1117 & n.6, 1118 & n.7, 1121 (9th Cir. 2020) (Graber, J.)
(relying on extra-record studies, including “[i]n other
contexts” like smoking, to support the majority’s
conclusion). Nobody in today’s majority batted an eye. See
Mai v. United States, 

, 1082–83, 1097 (9th Cir.
2020) (en banc) (containing multiple dissents from the denial
of rehearing en banc without a single member of today’s
majority joining).
    The majority doesn’t dispute (because it can’t) that the
Mai panel relied on extra-record materials to directly support
the outcome in that case. Instead, the majority belatedly
attempts to justify that reliance because the extra-record
materials existed in “publicly available scientific studies”
and because “the parties had asked [the court] to assess the
scientific evidence.”        Okay.       Whatever post-hoc
rationalization the majority offers now, nothing alters that
the Mai panel felt free, so long as it was rejecting a Second
Amendment claim, to cite and directly rely on facts that were
neither in the record nor cited by the parties.
     In contrast, as I’ve now explained at length, the
conceptual point I’m making in both the written and oral
portions of this dissent in no way relies on any specific or
unique facts—“scientific” or otherwise. The video portion
of my dissent doesn’t engage in any factfinding. It makes a
broad conceptual point that can be easily illustrated by a
literal universe of commonly known objects without being
tethered to any specific facts about those objects. But if my
colleagues were genuinely bothered by referencing non-
record facts in Second Amendment cases, maybe they would
                           DUNCAN V. BONTA                            145


have voted for en banc review in Mai—a case where the
panel expressly relied on non-record facts to drive the
outcome in that case. 7
    There is also a heads-I-win, tails-you-lose quality to the
majority’s crocodile tears over the supposed non-record
facts in my video dissent. Remember, it is the majority,
urged on by California, that has introduced a plainly
conceptually      flawed     but     supposedly      fact-based
constitutional test, and then purported to invent a farcical
factual distinction to support its constitutional conclusion. It
cannot be the case that, when judges make up such
conceptually flawed constitutional tests, the further the
invented test is from factual reality the more insulated it is
from criticism. The majority’s real beef with my video is
not that it introduces any new facts, but that it unmasks their
invented constitutional test as obviously grounded in a
factual fantasy.
    It would be one thing for me to introduce the majority’s
fact-based constitutional concept for the first time in my

7
   The panel’s reliance on extra-record materials in Mai was neither
tangential nor “offhand.” The panel directly and repeatedly relied on the
extra-record materials as factually supporting its decision. Yet the
majority now attempts to partially justify that reliance as merely taking
“judicial notice” because it supposedly only “took notice of the existence
of evidence of a particular sort, regardless of its accuracy.” But in Mai
itself, the panel never attempted to make such a claim. And for good
reason—it would have been a transparent misstatement. It is obvious to
anyone reading the Mai decision that the panel there was relying on the
substance of the claims made in extra-record materials, not just their
mere existence. See, e.g., Mai, 

 (“The authors found
that studies of persons released from involuntary commitment reported
a combined ‘suicide risk 39 times that expected.’ That extraordinarily
increased risk of suicide clearly justifies the congressional judgment ….”
(citation and footnote omitted)).
146                    DUNCAN V. BONTA


opinion, and then use my own (or someone else’s) firearms
knowledge to show why that concept belongs in our Second
Amendment jurisprudence. It is quite another for the
majority to purportedly rely on that factual concept,
introduce it into our jurisprudence, and then complain only
when I show the concept is completely divorced from reality.
California and the majority came up with their silly
conceptual test, not me. If some extra-record facts about
what is actually “integral” to firearms and what is a non-
integral “accessory” have entered the picture, that is not due
to my response, whether expressed via video or written
word. It is because the majority invited us to analyze a
nonexistent reality. Don’t shoot the messenger simply for
showing that this reality doesn’t exist.
    Ultimately, however, any debate over my supposedly
introducing facts is just a distraction. The majority is trying
to manufacture a controversy over the medium I chose to
make my point. But the force of my argument is the same
regardless of the format. The majority’s new test was never
based on some deep factual understanding gleaned from
experts and well-observed reality. It was concocted based
on the majority searching for some way—any way—to
declare high-capacity magazines not protected by the
Second Amendment. If nothing else, my colleagues are at
least consistent because doing so is in line with this court’s
long tradition of finding a way to neuter the Second
Amendment under whatever test the Supreme Court directs
us to apply. Now the majority projects onto my dissent its
insecurities about the very flawed factual concept it
contrived to do so. If you don’t like the video portion of my
dissent, then don’t watch it. But don’t let that distract you
from grasping the conceptual absurdity of the novel test the
                      DUNCAN V. BONTA                     147


majority has concocted to, once again, justify its refusal to
apply the Second Amendment.
                           * * *
    To sum it up: the majority’s rationale in this case,
followed to its (il)logical conclusion, means that now—
perhaps even more so than before Bruen—only the jankiest
guns are even facially protected by the Second Amendment.
And even those can be banned outright consistent with the
Second Amendment so long as the government can find a
historical analogue with the flimsiest connection to the
challenged law. Despite the Supreme Court’s intervention,
we’re right back where we started when it comes to the
Second Amendment, “trimm[ing] back that right at every
opportunity.” Duncan V, 

 (VanDyke, J.,
dissenting). Except worse. It sadly seems our court has
somehow now established an even more government-
friendly version of the very interest balancing the Supreme
Court rejected in Bruen. In doing so today, this court once
again improves its undefeated record against the Second
Amendment, demonstrating both its misunderstanding of
firearms and its disdain for the People’s constitutional right
to have them in the process.
   And once again, I respectfully dissent.