Under California law, a firearm qualifies as an assault weapon if it appears on the state’s list of banned makes and models, if it has certain features combined with a detachable magazine, or if it crosses specific size or caliber thresholds. The rules live mainly in Penal Code sections 30510 and 30515, and they apply to semiautomatic rifles, pistols, shotguns, and a catch-all category for firearms that don’t fit any of those three shapes. Possessing an unregistered assault weapon is a criminal offense punishable by up to a year in county jail or a state prison sentence, so the exact contours matter.
Firearms Banned by Name
The oldest layer of the ban is a list of specific makes and models. If a firearm appears on it, the firearm is an assault weapon no matter how it’s configured.1California Legislative Information. California Code Penal Code 30510 – Assault Weapons
The rifle list is long. It covers 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 other named models.1California Legislative Information. California Code Penal Code 30510 – Assault Weapons
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 a court declared to be an assault weapon under former Penal Code 12276.5.1California Legislative Information. California Code Penal Code 30510 – Assault Weapons
Named firearms could only be kept lawfully by owners who registered them with the California Department of Justice during a statutory window. Those windows are closed, and no new registrations are accepted.
Semiautomatic Rifles: The Feature Test
Penal Code 30515 adds a second layer: a features-based test. For a semiautomatic centerfire rifle, the test starts with the magazine. If the rifle can accept a detachable magazine, one prohibited feature is enough to make it 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, a thumbhole stock, a folding or telescoping stock, a grenade or flare launcher, a flash suppressor, and a forward pistol grip.2California Legislative Information. California Code PEN 30515 – Assault Weapons
The classification turns on the combination. A rifle with a detachable magazine plus any one of those features is an assault weapon. Take away the detachable magazine, or strip every listed feature, and the rifle falls outside this test.
Semiautomatic Pistols: The Feature Test
Pistols work similarly. A semiautomatic pistol without a fixed magazine is an assault weapon if it has any one of four features: a threaded barrel capable of accepting a flash suppressor, forward handgrip, or silencer; a second handgrip; a barrel shroud (a covering attached to or encircling the barrel that lets the shooter fire without burning their hand, not counting a slide that encloses the barrel); or the ability to accept a detachable magazine at a location other than the pistol grip.2California Legislative Information. California Code PEN 30515 – Assault Weapons
Separately, a semiautomatic pistol with a fixed magazine is an assault weapon if that magazine can hold more than 10 rounds.2California Legislative Information. California Code PEN 30515 – Assault Weapons
Semiautomatic Shotguns: The Feature Test
Shotguns have their own rules. The first shotgun test requires a combination of two features: a folding or telescoping stock, paired 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 test is simpler and sweeps in more firearms. Any semiautomatic shotgun that does not have a fixed magazine is an assault weapon, with no additional features required.2California Legislative Information. California Code PEN 30515 – Assault Weapons
Any shotgun with a revolving cylinder is also an assault weapon, regardless of whether it is semiautomatic or has any other features.2California Legislative Information. California Code PEN 30515 – Assault Weapons
The “Other” Category for Firearms That Aren’t Rifles, Pistols, or Shotguns
Effective September 2020, California added rules for semiautomatic centerfire firearms that don’t fit the rifle, pistol, or shotgun classifications. These are often called “Other” assault weapons, and the test combines the rifle and pistol feature lists.3State of California – Department of Justice – Office of the Attorney General. Other Assault Weapon Information
An “Other” firearm without a fixed magazine is an assault weapon if it 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 with a fixed magazine that holds more than 10 rounds also qualifies, as does one with an overall length under 30 inches.3State of California – Department of Justice – Office of the Attorney General. Other Assault Weapon Information
People who lawfully possessed an “Other” assault weapon before September 1, 2020, had until December 31, 2021, to register it. That window is closed.3State of California – Department of Justice – Office of the Attorney General. Other Assault Weapon Information
Size and Caliber Alone Can Make a Firearm an Assault Weapon
Some firearms qualify without any feature test at all.
A semiautomatic centerfire rifle with an overall length under 30 inches is an assault weapon regardless of its features or magazine setup. The measurement is taken in the shortest configuration that still allows the rifle to fire, so folding or 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, possessing, manufacturing, selling, or importing a .50 BMG rifle in California has been illegal unless the owner registered it with the Department of Justice by April 30, 2006.4California Department of Justice. .50 BMG Rifles – Assembly Bill 50 Possessing an unregistered .50 BMG rifle carries a fine of up to $1,000, up to a year in county jail, or both. Manufacturing, selling, or lending one is a felony punishable by four, six, or eight years in state prison.5Justia. California Code Penal Code 30600-30675 – .50 BMG Rifles
Fixed Magazines and Featureless Builds
Because the rifle and pistol feature tests both depend on the firearm accepting a detachable magazine, owners have two paths to keep otherwise-prohibited configurations legal.
The first is a fixed magazine. The statute defines this as an ammunition feeding device contained in, or permanently attached to, the firearm so that it cannot be removed without disassembling the firearm’s action.2California Legislative Information. California Code PEN 30515 – Assault Weapons In practice, the shooter has to break the action open (typically by separating the upper and lower receivers on an AR-platform rifle) before the magazine can be released. A rifle with a true fixed magazine can keep every feature on the prohibited list and remain outside the assault weapon definition, so long as the magazine holds no more than 10 rounds. California’s separate ban on magazines over 10 rounds applies independently.
The second path is a featureless build. The owner removes every prohibited feature and keeps a standard detachable magazine. Common modifications include swapping a pistol grip for a fin grip or Thordsen-style stock, pinning or removing a telescoping stock, and replacing a flash suppressor with a muzzle brake. Either path works.
Penalties and the Current Registration Status
Unlawful possession of an assault weapon is punishable by up to a year in county jail or by a state prison sentence. It’s a wobbler, meaning prosecutors can charge it as either a misdemeanor or a felony.6California Legislative Information. California Code PEN 30605 – Assault Weapon Possession
A narrow exception applies to first-time offenders who possessed the firearm before it was reclassified as an assault weapon, tried but failed to register it in time, were found with no more than two such firearms, and ultimately relinquished the weapon. Those individuals face a maximum fine of $500 rather than jail.6California Legislative Information. California Code PEN 30605 – Assault Weapon Possession
Manufacturing, selling, distributing, transporting, importing, or lending an assault weapon is a straight felony carrying four, six, or eight years in state prison. Transferring one to a minor adds a consecutive one-year enhancement, and each weapon involved counts as a separate offense.7California Legislative Information. California Code PEN 30600 – Assault Weapon Manufacture and Distribution
No registration window is currently open for any category of assault weapon. A person who missed the applicable deadline cannot register the firearm after the fact, so a firearm meeting any of the definitions above and never registered during its window has no compliant possession path other than modifying it into a featureless or fixed-magazine configuration, or surrendering it.