The Second Amendment and Gun Control 

Ghost Guns and Large-Capacity Magazines 
By Robert Phillips, Deputy District Attorney (Ret).

The last half of March was a big month for gun control. As already reported in an article by Ray Hill, Legal Updates’ in-house Santa Rosa Junior College Professor Emeritus, the U.S. Supreme Court in a 7-2 decision held that “ghost guns” or “undetectable weapons” (build-it-yourself gun kits, mainly bought online, that include all the parts of a gun but are untraceable when assembled) are illegal unless embedded with a serial number (See Legal Updates reference # CAB10041) and (See Bondi v. Vanderstok [Mar. 26, 2025] 604 U.S. [2025 U.S. LEXIS 1280].)  

The case provides an interpretation of several federal statutes involving the importation, manufacturing or dealing in firearms, and, being from the U.S. Supreme Court, affects the entire nation.  

Less than a week earlier, an en banc (11-justice) panel of the Ninth Circuit Court of Appeals rendered a decision concerning the legality of what are commonly referred to as “large-capacity magazines,” a magazine that holds more than 10 rounds of ammunition (as defined in P.C. § 16740). On March 20, the Ninth Circuit held in Duncan v. Bonta (9^th Cir. Mar. 20, 2025) F.4^th [2025 U.S.App. LEXIS 6528], that California has the constitutional authority to make the possession of large-capacity magazines illegal, and, in fact, has done so. 

The primary issue in Duncan was whether California’s attempt to regulate large-capacity magazines was constitutional under the U.S. Supreme Court decision in New York State Rifle & Pistol Assn v. Bruen (2022) 597 U.S. 1. In Bruen, the High Court held that when the Second Amendment’s plain text covers an individual’s conduct, the Constitution presumptively protects that conduct from any interference by a state or federal legislature. To overcome that presumption, the government must justify its attempt at imposing a regulation by demonstrating that its proposed legislation is consistent with the nation’s historical tradition of firearm regulation, as understood by the Founding Fathers. 

The Second Amendment itself 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,” creating an individual right to keep and bear arms for self-defense. (District of Columbia v. Heller (2008) 554 U.S. 570, 599, 602.) The right applies to the states via the Fourteenth Amendment’s due process clause. (McDonald v. City of Chicago (2010) 561 U.S. 742, 750.)  

Motivated by mass shootings, California has been chipping away at large-capacity magazines for some time. In 2000, the manufacturing, importation, or sale in the state was made illegal. (P.C. § 12020(a)(2)) In 2010 and 2013, the Legislature outlawed the purchasing or receipt of large-capacity magazines. (P.C. § 32310(a)) And then finally, effective in 2017, the possession of large-capacity magazines was outlawed via both legislation and the voter approved Proposition 63. (P.C. § 32310(c))  

Virginia Duncan and other plaintiffs filed the instant lawsuit arguing that the Second Amendment protected their right to possess their large-capacity magazines. In its Duncan v. Bonta decision, however, the Ninth Circuit disagreed. In reaching this conclusion, the court had to consider whether Bruen allowed for California’s legislation as it attempted to outlaw large-capacity magazines. Ultimately, the court rejected the plaintiffs’ Second Amendment challenge for two reasons:  

First, the plain text of the Second 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 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,” as required under the Bruen decision (597 U.S. at pg. 17). California’s law fits within the traditions of protecting innocent people 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, i.e., mass shootings. 

Bottom line is that P.C. § 32310, prohibiting the possession of large-capacity magazines (at subdivision (c)), is constitutional.  

If you have one, subdivision (d) tells you what you must do to divest yourself of it. Note also, however, that the ban on possession of large-capacity magazines exempts certain people, such as active or retired law enforcement officers and security guards for armored vehicles. (P.C. §§ 32400-32455)