Under California law, a firearm is an “assault weapon” if it falls into any one of three buckets: it appears by name on the state’s banned-model list in Penal Code 30510, it has a prohibited combination of features under Penal Code 30515, or it crosses a size or caliber threshold the statute treats as disqualifying on its own. The California assault weapon definition is layered, so a rifle, pistol, or shotgun can qualify through any of these routes independently.1California Legislative Information. California Code Penal Code 30510 – Assault Weapons2California Legislative Information. California Code PEN 30515 – Assault Weapons
Firearms Banned by Name
The oldest layer of the definition is a straight list of makes and models. If a firearm is on the list, it is an assault weapon no matter how it is configured or what features it does or does not have.1California Legislative Information. California Code Penal Code 30510 – Assault Weapons
On the rifle side, the list sweeps in all AK series rifles (including Chinese-made models, Norinco, Poly Technologies, and MAADI variants), UZI and Galil rifles, the Colt AR-15 series, the Beretta AR-70, HK-91 through HK-PSG-1, several MAC-type firearms, the SKS with a detachable magazine, SIG models, the Steyr AUG, the Bushmaster Assault Rifle, and roughly a dozen more. The pistol list names the UZI pistol, Encom MP-9 and MP-45, several MAC-type pistols, the Intratec TEC-9, Sites Spectre, Sterling MK-7, Calico M-950, and Bushmaster Pistol. The shotgun list names the Franchi SPAS 12 and LAW 12, the Striker 12, and the Streetsweeper. The statute also captures any firearm that a court declared to be an assault weapon under former Penal Code 12276.5.1California Legislative Information. California Code Penal Code 30510 – Assault Weapons
Lawful possession of a named firearm requires that the owner registered it with the California Department of Justice during one of the statutory registration windows. Those windows are closed.
When Features Make a Rifle an Assault Weapon
Penal Code 30515 adds a second layer that captures firearms not listed by name. For a semiautomatic centerfire rifle, the test turns on the magazine. If the rifle can accept a detachable magazine, then a single prohibited feature is enough to classify it as an assault weapon.2California Legislative Information. California Code PEN 30515 – Assault Weapons
The prohibited features for rifles are:
- A pistol grip that protrudes conspicuously beneath the action of the weapon
- A thumbhole stock
- A folding or telescoping stock
- A grenade launcher or flare launcher
- A flash suppressor
- A forward pistol grip
A detachable magazine plus any one of those features makes the rifle an assault weapon. Take the detachable magazine out of the equation, or strip every listed feature from the rifle, and the rifle falls outside this part of the definition.2California Legislative Information. California Code PEN 30515 – Assault Weapons
When Features Make a Pistol an Assault Weapon
Semiautomatic pistols follow the same basic structure. A semiautomatic pistol without a fixed magazine is an assault weapon if it has any one of these features:2California Legislative Information. California Code PEN 30515 – Assault Weapons
- A threaded barrel capable of accepting a flash suppressor, forward handgrip, or silencer
- A second handgrip
- A barrel shroud, meaning a covering attached to or encircling the barrel that lets the shooter fire without burning their hand (a slide that encloses the barrel does not count)
- The ability to accept a detachable magazine at a location other than the pistol grip
A separate rule covers fixed-magazine pistols: a semiautomatic pistol with a fixed magazine that can hold more than 10 rounds is also an assault weapon.2California Legislative Information. California Code PEN 30515 – Assault Weapons
When Features Make a Shotgun an Assault Weapon
Shotguns are treated differently. The first shotgun test requires a combination of two features rather than one: a folding or telescoping stock, combined with a pistol grip that protrudes conspicuously beneath the action, a thumbhole stock, or a vertical handgrip.2California Legislative Information. California Code PEN 30515 – Assault Weapons
The second shotgun test is broader. Any semiautomatic shotgun that does not have a fixed magazine is an assault weapon, with no additional features required. And any shotgun with a revolving cylinder is automatically an assault weapon, regardless of whether it is semiautomatic or what features it carries.2California Legislative Information. California Code PEN 30515 – Assault Weapons
The “Other” Catch-All Category
Effective September 2020, California added a category for semiautomatic centerfire firearms that are not rifles, pistols, or shotguns. These are commonly called “Other” assault weapons, and the feature list essentially merges the rifle and pistol tests.3State of California – Department of Justice – Office of the Attorney General. Other Assault Weapon Information
A semiautomatic centerfire firearm that is not a rifle, pistol, or shotgun qualifies if it lacks a fixed magazine and has any one of the following: a conspicuous pistol grip, a thumbhole stock, a folding or telescoping stock, a grenade or flare launcher, a flash suppressor, a forward pistol grip, a threaded barrel capable of accepting a suppressor or handgrip, a second handgrip, a barrel shroud, or the ability to accept a detachable magazine outside the pistol grip. An “Other” firearm also qualifies if it has a fixed magazine holding more than 10 rounds, or if its overall length is under 30 inches.3State of California – Department of Justice – Office of the Attorney General. Other Assault Weapon Information
Size and Caliber Triggers
Some firearms are assault weapons based on their dimensions or caliber alone, with no feature test applied.
Any semiautomatic centerfire rifle with an overall length under 30 inches is an assault weapon, no matter what features it has or whether its magazine is fixed or detachable. The measurement is taken in the shortest configuration that still allows the rifle to fire, so folding and telescoping stocks are collapsed before measuring.2California Legislative Information. California Code PEN 30515 – Assault Weapons
Rifles chambered for the .50 BMG cartridge sit in their own statutory category. Since January 1, 2005, it has been illegal to possess, manufacture, sell, or import a .50 BMG rifle in California unless the owner registered it with the Department of Justice by April 30, 2006.4California Department of Justice. .50 BMG Rifles – Assembly Bill 50 A .50 BMG rifle is regulated separately from assault weapons but under a parallel scheme.
Fixed-Magazine and Featureless Builds
Because the feature tests for rifles and pistols hinge on the firearm being able to accept a detachable magazine, two configurations exist that keep a firearm with otherwise-restricted parts outside the definition.
The first is a true fixed magazine. The statute defines a fixed magazine as an ammunition feeding device contained in, or permanently attached to, the firearm in a way that it cannot be removed without disassembling the firearm’s action.2California Legislative Information. California Code PEN 30515 – Assault Weapons In practical terms on an AR-platform rifle, the shooter has to break open the action, typically by separating the upper and lower receivers, before releasing the magazine. A rifle with a true fixed magazine can keep every feature on the prohibited list and still fall outside the feature test, provided the magazine holds no more than 10 rounds. California’s separate ban on magazines over 10 rounds applies on its own.
The second path is a “featureless” build: the owner leaves the standard detachable magazine in place and removes every prohibited feature. Common modifications include swapping a pistol grip for a fin grip or Thordsen-style stock, pinning or removing a telescoping stock, and running a muzzle brake rather than a flash suppressor.
Why the Classification Matters
Whether a firearm meets the California assault weapon definition decides whether possessing it is a crime. Unlawful possession is a wobbler, punishable by up to a year in county jail or by imprisonment in state prison, charged as either a misdemeanor or a felony.5California Legislative Information. California Code PEN 30605 – Assault Weapon Possession Manufacturing, selling, distributing, transporting, importing, or lending an assault weapon is a straight felony punishable by four, six, or eight years in state prison, with each weapon treated as a separate offense.6California Legislative Information. California Code PEN 30600 – Assault Weapon Manufacture and Distribution
Owners should also know that no registration window is currently open for any category of assault weapon. The bullet-button registration period closed in 2018, briefly reopened under the federal court order in Sharp v. Becerra from January 13, 2022 through April 12, 2022 for people who had attempted to register before the original deadline, and then closed again.7State of California – Department of Justice – Office of the Attorney General. Bullet-Button Assault-Weapon Registration Information The “Other” assault weapon window ran from October 1 through December 31, 2021.3State of California – Department of Justice – Office of the Attorney General. Other Assault Weapon Information A firearm that meets any of the tests above and is not already registered cannot be registered after the fact, which is why the definition is worth working through part by part before buying, building, or modifying anything.