Owning an assault rifle in California is illegal unless the firearm was registered with the state Department of Justice before the applicable deadline, and those registration windows have closed. That said, California’s law targets a specific category it calls “assault weapons,” defined by physical features rather than by how the gun fires, so it is still possible to legally own an AR-15-style rifle if the build avoids every prohibited feature or uses a fixed magazine. Getting the configuration wrong is a wobbler offense that can be charged as a felony.
What California Actually Bans
California law uses the term “assault weapon,” not “assault rifle.” True assault rifles are select-fire weapons capable of fully automatic fire, and those have been effectively off-limits to new civilian ownership nationwide under federal law since 1986. What California restricts is a much broader category of semiautomatic firearms.
The state classifies assault weapons two ways. The first is a named-models list originally created by the Roberti-Roos Assault Weapons Control Act of 1989. It now includes hundreds of specific rifles, pistols, and shotguns, and the California Department of Justice maintains the full catalog.
The second approach is the features test under Penal Code 30515, and this is the one that catches most owners off guard. A semiautomatic centerfire rifle with a detachable magazine is an assault weapon if it has any one of the following:
- A pistol grip that protrudes conspicuously beneath the action
- A thumbhole stock
- A folding or telescoping stock
- A flash suppressor
- A grenade or flare launcher
- A forward pistol grip
One feature is enough.1State of California Department of Justice – Office of the Attorney General. Assault Weapon Characteristics A semiautomatic centerfire rifle with a fixed magazine holding more than ten rounds, or with an overall length under 30 inches, also qualifies regardless of other features.2California Legislative Information. California Penal Code 30515 Certain semiautomatic pistols and shotguns with comparable features fall under the same restrictions. A standard, out-of-the-box AR-15 almost always meets the definition.
How to Own an AR-Style Rifle Legally
Because the law targets specific combinations of features, two compliance paths exist for owning an AR-style rifle in California.
Featureless Build
A featureless rifle keeps a standard detachable magazine but strips out every prohibited feature. In practice, that means replacing the pistol grip with a fin grip or similar alternative that prevents the web of the hand from dropping below the trigger, using a fixed stock instead of a telescoping one, swapping any flash suppressor for a muzzle brake or compensator, and removing any forward pistol grip. A muzzle brake redirects gas to reduce recoil but does not suppress the visible flash, and that functional difference is what keeps it legal.2California Legislative Information. California Penal Code 30515 The rifle handles differently than a standard AR but is fully legal.
Fixed-Magazine Build
The alternative is to fix the magazine in place. Under California regulations, a “fixed magazine” is one that cannot be removed without disassembling the firearm’s action.3California Department of Justice. Information Bulletin Re Application of Californias Assault Weapon Laws to the Fixed It For You Fixed Magazine Cage For an AR-15, that means separating the upper and lower receivers before the magazine can come out. With the magazine fixed, the rifle can keep a pistol grip, telescoping stock, and flash suppressor.
The tradeoff is slower reloading. The DOJ has also pushed back on devices that claim to create a fixed magazine but leave the magazine well functionally open; if a device lets you swap magazines without breaking the action apart, the DOJ does not treat it as compliant.
Either way, the magazine itself cannot hold more than ten rounds. California’s large-capacity magazine ban applies to featureless and fixed-magazine builds alike.
You Cannot Register One Now
Each time California expanded its assault weapon definition, the legislature opened a limited window for existing owners to register grandfathered firearms with the DOJ. The most recent window closed on June 30, 2018.4California Legislative Information. California Penal Code 30900 Registration required electronic submission of the firearm’s details and the owner’s information, along with a $15 fee per transaction.5Legal Information Institute. Cal Code Regs Tit 11, 5475 – Registration of Assault Weapons
There is no retroactive registration. An assault weapon that should have been registered but wasn’t is illegal to possess. The realistic options at that point are to modify it into a compliant configuration, transfer it to a licensed dealer, move it out of state permanently, or surrender it to law enforcement.
If you did register before the deadline, keep the DOJ confirmation somewhere accessible. It is the only documentation that proves lawful possession if law enforcement ever questions it.
Penalties for Illegal Possession
Possessing an unregistered assault weapon is a wobbler under Penal Code 30605.6California Legislative Information. California Penal Code 30605 A misdemeanor conviction carries up to one year in county jail and a fine of up to $1,000. A felony conviction carries a state prison term of 16 months, two years, or three years. In narrow circumstances the charge can be reduced to an infraction with a $500 fine, though prosecutors rarely offer that without strong mitigating factors.
Manufacturing, distributing, importing, or selling an assault weapon is a straight felony. The prison term is four, six, or eight years.7California Legislative Information. California Penal Code 30600 When multiple firearms are involved, sentences can run consecutively. Not knowing that your rifle qualifies as an assault weapon is not a recognized defense.
The Federal Firearms Disability
A felony conviction under California’s assault weapon laws also triggers a permanent federal bar on gun ownership. Under 18 U.S.C. § 922(g), anyone convicted of a crime punishable by more than one year in prison is prohibited from possessing any firearm or ammunition anywhere in the country.8Office of the Law Revision Counsel. 18 USC 922 – Unlawful Acts A single felony conviction can end your ability to own any gun in any state for life.
Situations That Trip People Up
Moving to California
You cannot bring an assault weapon with you when you move to California, even if you owned it lawfully in your prior state. California does not offer new-resident registration. Sell it, store it out of state, have it permanently modified into a California-compliant configuration before it crosses the state line, or surrender it.
Transporting Through the State
Passing through California with a firearm that qualifies as an assault weapon here is different from stopping. The Firearm Owners’ Protection Act, 18 U.S.C. § 926A, allows interstate transport of a firearm from one state where you may lawfully possess it to another, provided the weapon is unloaded and stored where it is not readily accessible from the passenger compartment.9Office of the Law Revision Counsel. 18 USC 926A – Interstate Transportation of Firearms In a vehicle without a separate trunk, it must be in a locked container other than the glove compartment or console. The protection covers continuous travel only; stopping in California for any purpose beyond basic travel needs can void it.
Inheriting a Registered Assault Weapon
When a registered owner dies, the firearm generally cannot pass to heirs. Assault weapons may only be transferred to a licensed firearms dealer or to a law enforcement agency. The estate’s realistic options are surrender to law enforcement, transfer through a licensed dealer to an out-of-state buyer in a state where the weapon is legal, or destruction. The narrow exception is an heir who independently qualifies for an exemption, such as a sworn peace officer with written agency authorization to possess the weapon.
This inheritance trap is worth planning around. Without instructions in an estate plan, a family could unknowingly commit a felony simply by keeping the weapon after the owner’s death.
Private Sales and Gifts
Selling, gifting, or lending an assault weapon between private citizens is prohibited. That covers gun shows, online marketplaces, and person-to-person transactions. Penal Code 30600 makes any such transfer a felony carrying four to eight years in prison.7California Legislative Information. California Penal Code 30600
The Law Is Being Challenged, but It Is Still Enforced
California’s assault weapon ban is the subject of an active constitutional challenge in Miller v. Bonta, currently before the Ninth Circuit Court of Appeals. In 2021, a federal district court ruled that portions of the Assault Weapons Control Act violated the Second Amendment and entered a permanent injunction. The California Attorney General obtained an administrative stay from the Ninth Circuit, so the ban remains fully enforceable while the appeal proceeds.10State of California – Department of Justice – Office of the Attorney General. Defending Californias Commonsense Firearms Laws
The case was held in abeyance while the Ninth Circuit decided Duncan v. Bonta, a related challenge to California’s large-capacity magazine ban. After that en banc decision, the court ordered supplemental briefing in Miller in early 2025. The U.S. Supreme Court has shown interest in whether assault weapon bans survive Second Amendment scrutiny, but no ruling has come down.
The practical takeaway is straightforward. California’s assault weapon laws are enforceable today, and relying on a future court decision to legalize a weapon you currently possess illegally is a strategy that could put you in prison while you wait.