The United States Court of Appeals for the Ninth Circuit just handed Second Amendment supporters a massive win. In a 2-1 decision issued July 24, 2025, a three-judge panel in Rhode v. Bonta, No. 24-542, struck down California’s ammunition background check regime as unconstitutional under the Second Amendment — affirming the district court’s permanent injunction against enforcement of a law that had no analog anywhere in American history.
This is a big deal, and I want to walk through exactly why the court got it right.
Ammunition Is an “Arm” — Full Stop
The court’s first move was textual, and it’s the right one. The Second Amendment protects “the right of the people to keep and bear Arms.” California’s position required courts to read “Arms” narrowly enough to exclude ammunition — essentially arguing that you have a constitutional right to own a firearm that can’t fire. That doesn’t hold up.
Judge Sandra S. Ikuta, writing for the majority, held that firearms are protected arms under the Second Amendment, and because a firearm is functionally useless without ammunition, ammunition necessarily falls within that textual protection. The court also recognized — correctly, in my view — that the right to acquire arms is implicit in the right to keep and bear them. You can’t keep something you can’t obtain.
California’s Proposition 63, enacted in 2016 and effective July 2019, required background checks for every single ammunition purchase. Under this regime, law-abiding Californians — including lead plaintiff Kim Rhode, a six-time Olympic medalist and competitive shooter — faced repeated fees and hurdles every time they wanted to buy a box of cartridges. Once the court found that the regulation burdened textually-protected conduct, the burden shifted to the state to justify the law with historical tradition.
California could not meet that burden.
California Led with Its Chin
Here is where California’s legal strategy became almost self-defeating. The state was openly proud of Proposition 63 as the “first in the nation” ammunition background check law. I found that remarkable, because by claiming that distinction, California essentially conceded the point. If no jurisdiction in American history — not one — had ever imposed background checks on ammunition purchases, then by definition there is no “long-standing tradition of firearms regulation” analogous to this law. The Bruen framework requires historical tradition rooted in the founding era. “First ever” is the opposite of that.
California threw four sets of historical laws at the court, and the majority dismantled each one. Loyalty-oath disarmament of Tories during the Revolutionary War? That addressed enemy combatants in a hot war, not peaceable citizens buying ammunition. Concealed carry licensing? That’s a one-time check to verify a person isn’t a prohibited possessor — nothing like compelling every gun owner to submit to a background check every time they purchase fifty rounds. Post-Civil War licensing regulations? As I have written about in the Harvard Journal of Law and Public Policy, interpretations of the Second Amendment must laser-focus on 1791, when the Bill of Rights was ratified. Late-nineteenth-century laws — enacted more than a hundred years after many of the Founders were dead — carry little weight. Finally, colonial-era gunpowder storage rules were fire-safety and consumer-protection measures, not restrictions on who could acquire ammunition.
California also leaned on Bruen footnote 9’s suggestion that objective, non-discretionary shall-issue permitting schemes are presumptively constitutional. The court correctly rejected that as dicta that says nothing about forcing background checks on every ammunition transaction.
What the Court Actually Said
In summing up its 54-page opinion, the Ninth Circuit wrote:
By subjecting Californians to background checks for all ammunition purchases, California’s ammunition background check regime infringes on the fundamental right to keep and bear arms. Because California’s ammunition background check regime violates the Second Amendment, the district court did not abuse its discretion in granting a permanent injunction.
Judge Jay S. Bybee dissented. The 2-1 split makes an en banc petition by California a near-certainty.
What Comes Next
The Ninth Circuit has a habit of granting en banc review in major Second Amendment cases to reverse pro-2A panel decisions — we’ve seen it with assault-weapon bans and magazine-capacity limits. Whether en banc review gets granted on this one is, in my estimation, less certain than those cases. An ammunition-background-check regime with zero historical support is a particularly hard case for California to defend. But I fully expect California to file that petition, and we’ll be watching closely.
For now, the permanent injunction stands, Proposition 63’s background check machinery is blocked, and the Ninth Circuit has issued one of its most consequential Second Amendment rulings in years. The Bruen framework — text first, then historical tradition — is working exactly as the Supreme Court designed it.
This article is based on analysis by Professor Mark W. Smith, constitutional attorney and Host of the Four Boxes Diner 2nd Amendment channel. Watch the original video here. This does not constitute legal advice.