Third Circuit Split Could Push California Magazine Ban Before Supreme Court

The challengers to California’s magazine ban are urging the U.S. Supreme Court to take up Duncan v. Bonta after the Third Circuit expressly rejected the Ninth Circuit’s reasoning and struck down New Jersey’s nearly identical restriction.

In a supplemental brief filed Monday, August 3, attorneys for Virginia Duncan, the California Rifle & Pistol Association, and the other petitioners told the justices that there is now an open and acknowledged split between two federal appellate courts sitting en banc.

The Ninth Circuit says California may criminalize possession of magazines capable of holding more than ten rounds. The Third Circuit says magazines—including those holding more than ten rounds—are “Arms” protected by the Second Amendment and cannot be banned when they are commonly possessed for lawful purposes. The Duncan petitioners are asking the Supreme Court to settle the question.

Third Circuit Rejects the Ninth Circuit’s Magazine-Ban Logic

On July 17, 2026, the en banc Third Circuit ruled 10-5 that New Jersey’s ban on magazines holding more than ten rounds violated the Second Amendment. The court also struck down New Jersey’s prohibition on commonly owned semiautomatic rifles. More importantly for Duncan, the Third Circuit directly addressed and rejected the Ninth Circuit’s defense of California’s magazine ban.

The Ninth Circuit’s primary theory was that magazines are not “Arms” at all. Instead, it treated them as accessories or “accoutrements” outside the Second Amendment’s plain text.

The Third Circuit rejected that argument as inconsistent with the Supreme Court’s instructions in New York State Rifle & Pistol Association v. Bruen.

A magazine facilitates the use of a firearm for armed self-defense. A semiautomatic firearm cannot perform its ordinary repeating function without an ammunition-feeding device. Calling that essential component an “accessory” does not remove it from the Constitution. The Third Circuit therefore concluded that magazines are “Arms” and are presumptively protected by the Second Amendment. That conclusion applies to all magazines, not merely those holding ten rounds or fewer.

The Constitution Does Not End at the Eleventh Round

The Third Circuit was particularly critical of the Ninth Circuit’s alternative suggestion that a ten-round magazine might be constitutionally protected while an eleven-round magazine is not. As the Third Circuit explained, it cannot be that a magazine holding ten rounds is an “Arm” covered by the Second Amendment while one holding eleven rounds falls outside the constitutional text.

There is no ten-round limitation in the Second Amendment. There was no such dividing line in the Founding-era understanding of the right to keep and bear arms. Ten rounds is a political number selected by anti-gun legislators, not a constitutional boundary.

The Ninth Circuit also reasoned that larger magazines could be banned because firearms remain capable of operating with smaller ones. The Third Circuit properly rejected that claim as well. The Second Amendment does not protect only the minimum equipment necessary to make a firearm function. The government cannot avoid constitutional scrutiny by arguing that citizens should make do with a less capable substitute.

That theory could be used to justify nearly any arms restriction. A state could argue that a five-round magazine is sufficient because a firearm still operates. It could then reduce the limit to three rounds or one.

The right to keep and bear arms would become a privilege to possess whatever reduced-capacity equipment lawmakers decide is acceptable for ordinary citizens. That is not how enumerated rights work.

Common Use Does Not Mean Rounds Fired

The Third and Ninth Circuits also disagree over how the Supreme Court’s common-use standard should be applied. The Ninth Circuit dismissed the common-use test as too simplistic and focused on whether people frequently fire more than ten rounds during individual defensive incidents. That badly misunderstands the constitutional inquiry.

The question is whether an arm is commonly possessed or used by law-abiding citizens for lawful purposes, not whether its full capacity is regularly expended during a shooting. Millions of Americans own firearms they hope never to fire in self-defense. They carry spare magazines they may never need. They keep ammunition reserves that may never be used. None of that makes those arms or components constitutionally unprotected.

A person does not lose the right to possess an effective defensive tool merely because he successfully resolves most confrontations without firing every available round. The Third Circuit held that magazines capable of holding more than ten rounds are in common use for lawful purposes regardless of how frequently defenders fire more than ten rounds.

Its conclusion was direct: “Bans on weapons in common use for lawful purposes are unlawful.”

That is consistent with District of Columbia v. Heller. The Ninth Circuit’s preferred test is not.

Gunpowder Storage Laws Do Not Justify Magazine Bans

The Ninth Circuit also relied on Founding-era gunpowder-storage regulations to defend California’s magazine ban. Those historical laws generally regulated where large quantities of gunpowder could be stored to reduce the danger of accidental fires and explosions in populated areas. They did not prohibit ordinary citizens from possessing common weapons or impose ammunition-capacity limits.

The Third Circuit correctly found that gunpowder-storage laws are not relevantly similar to a modern ban on magazines.

This is where many lower courts have attempted to water down Bruen. Instead of requiring the government to identify a genuine historical tradition supporting the modern restriction, courts reach for any old law involving firearms, gunpowder, public safety, or dangerous conduct. But historical analogies must be more than vaguely related. The government must show a comparable burden imposed for a comparable reason.

A fire-prevention rule governing bulk gunpowder storage is not a historical analogue for banning possession of standard-capacity magazines that are commonly owned in the millions by law-abiding citizens.

Constitutional Rights Should Not Change at the State Line

The result of the split is that the same magazine may be constitutionally protected in Pennsylvania but prohibited in California. Residents of New Jersey, Pennsylvania, and Delaware are now protected by the Third Circuit’s conclusion that magazines holding more than ten rounds are covered by the Second Amendment. Residents of California, Oregon, Washington, and the rest of the Ninth Circuit remain subject to the opposite rule.

The Bill of Rights is not supposed to change when an American crosses from one federal judicial circuit into another.

The Supreme Court exists in part to resolve precisely this kind of conflict. When two federal courts of appeals issue irreconcilable en banc decisions concerning the scope of an enumerated constitutional right, only the Supreme Court can provide a nationally controlling answer.

The Duncan petitioners argue that the Court should grant their case, or the related Washington magazine case, Gator’s Custom Guns v. Washington, and consider the magazine question alongside Viramontes v. Cook County and Grant v. Higgins. The Supreme Court granted review in Viramontes and Grant on June 30, 2026, to address whether states may ban AR-15-style rifles consistent with the Second Amendment.

Gun-control states have pursued the same strategy against both categories. They relabel commonly owned rifles as “assault weapons” and standard magazines as “large-capacity magazines,” then insist that politically charged terminology removes ordinary arms from constitutional protection. It does not.

Gun Owners Have Waited Long Enough

The Duncan litigation has continued for more than a decade. The petitioners warn that merely holding the case until after Viramontes and Grant could lead to another procedural loop. The Supreme Court might later vacate the Ninth Circuit’s ruling and send the case back for reconsideration, allowing the Ninth Circuit to produce another decision and forcing the challengers to file yet another petition.

California gun owners should not have to endure another round of judicial delay while the state continues enforcing a ban against arms that another federal appellate court has already recognized as constitutionally protected.

The Third Circuit has exposed the weakness of the Ninth Circuit’s reasoning. The Supreme Court now has a clear circuit split, fully developed legal arguments, and an opportunity to resolve rifle and magazine bans together.

---

About Duncan Johnson:

Duncan Johnson is a lifelong firearms enthusiast and unwavering defender of the Second Amendment—where “shall not be infringed” means exactly what it says. A graduate of George Mason University, he enjoys competing in local USPSA and multi-gun competitions whenever he’s not covering the latest in gun rights and firearm policy. Duncan is a regular contributor to AmmoLand News and serves as part of the editorial team responsible for AmmoLand’s daily gun-rights reporting and industry coverage.

---