A rifle is California compliant when it stays outside the state’s definition of an “assault weapon” under Penal Code 30515. For a semi-automatic centerfire rifle, that means one of two builds: strip off the listed features (pistol grip, thumbhole stock, folding or telescoping stock, flash suppressor, forward grip, grenade or flare launcher) and run a detachable magazine of 10 rounds or fewer, or keep those features but lock the magazine so it can only come out by breaking the action open. Either way, the rifle has to be at least 30 inches overall, and the magazine cap of 10 rounds applies no matter which path you choose. Bolt-action, lever-action, and rimfire semi-automatics like a standard .22 LR aren’t subject to the features test at all.
What Puts a Rifle Over the Line
Penal Code 30515 classifies a semi-automatic centerfire rifle as an assault weapon in three situations. Trip any one of them and the rifle is illegal to possess without registration, which for most people is no longer available.
The first trigger is a rifle with a detachable magazine and any one of the following features: 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, or a forward pistol grip. One feature is enough.1California Legislative Information. California Penal Code 30515
The second trigger is a semi-automatic centerfire rifle with a fixed magazine that holds more than 10 rounds. Locking the magazine in place doesn’t save you if it accepts more than 10.1California Legislative Information. California Penal Code 30515
The third is a semi-automatic centerfire rifle with an overall length under 30 inches, regardless of features or magazine.1California Legislative Information. California Penal Code 30515
The “centerfire” word matters. A semi-automatic .22 LR with a pistol grip, telescoping stock, and a 25-round magazine isn’t an assault weapon under this statute because it fires rimfire ammunition. Other California laws (notably the magazine cap below) still apply.
The Featureless Build
Featureless is the more popular route because you keep a standard detachable magazine, which means normal reloads. The tradeoff is giving up every feature on the list.
The most noticeable change is at the grip. A standard AR-15 pistol grip gets swapped for a “fin grip” or wrap that prevents the thumb from encircling the grip. It feels awkward at first, and most shooters never fully love it, but it works. Adjustable stocks get replaced with fixed-length stocks or pinned in place. Flash suppressors come off and are typically replaced with muzzle brakes or compensators, which reduce recoil but don’t suppress flash. Any forward vertical grip has to go.2State of California – Department of Justice – Office of the Attorney General. Assault Weapons Laws (California and Federal Law)
The rifle looks unusual to anyone used to standard configurations but cycles and reloads the same way. You just can’t feed it a magazine holding more than 10 rounds.
The Fixed Magazine Build
Fixed magazine goes the other direction: keep the pistol grip, adjustable stock, and flash suppressor, but lock the magazine in place so it can’t be removed without disassembling the firearm action. Penal Code 30515(b) defines a fixed magazine as one that is contained in or permanently attached to the firearm and cannot be removed without disassembling the action.1California Legislative Information. California Penal Code 30515
On an AR-15 platform, this usually means a device that forces you to separate the upper and lower receivers before the magazine releases. Several aftermarket products modify the rear takedown pin to accomplish this. You push the pin, crack the receivers apart, swap the magazine, close the receivers, and keep shooting.
Reloading is noticeably slower than with a detachable magazine, which is the entire point from the legislature’s perspective. For range shooting many owners find it acceptable; for anyone who prioritizes fast reloads, featureless is usually the better choice.
Bullet Buttons No Longer Qualify
Before 2017, a “bullet button” (a recessed magazine release that required a tool to press) was the standard workaround. California closed that loophole. A bullet-button rifle doesn’t meet the fixed-magazine definition because the magazine still comes out without disassembling the action.3Cornell Law Institute. Cal. Code Regs. Tit. 11, 5471 – Explanation of Terms Related to Assault Weapon Designation Owners had until July 1, 2018 to register these rifles as assault weapons under Penal Code 30900; that window is closed, and an unregistered bullet-button rifle with banned features and a detachable magazine is now illegal to possess.4Cornell Law School. Cal. Code Regs. Tit. 11, 5470 – Registration of Assault Weapons Pursuant to Penal Code Section 30900(b)(1)
The 10-Round Magazine Cap
Separate from the assault weapon rules, California bars possessing, buying, selling, manufacturing, or importing a magazine that holds more than 10 rounds. This applies whether your rifle is featureless, fixed-magazine, or a bolt-action that otherwise wouldn’t be regulated at all.5California Legislative Information. California Penal Code 32310
Narrow exceptions exist for law enforcement, the military, and certain government agencies, but there is no general private-citizen exception. The definition excludes .22 caliber tubular feeding devices, tubular magazines in lever-action firearms, and any magazine permanently altered so it cannot hold more than 10 rounds.
The ban has been challenged in Duncan v. Bonta. In March 2025 the Ninth Circuit, sitting en banc, upheld it, and a Supreme Court cert petition was filed in August 2025.6Duke Center for Firearms Law. SCOTUS Gun Watch – Week of 8/25/25 Until the Supreme Court says otherwise, the 10-round cap is fully enforceable. Pending litigation is not a reason to keep larger magazines in California.
Length Rules
California stacks two length restrictions, both stricter than federal law. Under Penal Code 30515, any semi-automatic centerfire rifle under 30 inches overall is an assault weapon, period, regardless of features or magazine configuration.1California Legislative Information. California Penal Code 30515
Separately, a “short-barreled rifle” under state law is any rifle with a barrel under 16 inches or an overall length under 26 inches, and possessing one is a distinct criminal offense.7California Legislative Information. California Penal Code 17170 Federal law uses the same 16-inch barrel and 26-inch overall thresholds under the National Firearms Act.8Office of the Law Revision Counsel. 26 U.S. Code 5845 – Definitions
California does not recognize a federal NFA registration for a short-barreled rifle, so even a lawfully NFA-registered SBR cannot be possessed in the state. And the 30-inch overall-length threshold for assault weapon classification goes well above the federal 26-inch minimum. If you’re building a compact rifle, measure before you build.
Penalties for a Non-Compliant Rifle
Getting this wrong is a criminal matter, not an administrative one.
Possessing an unregistered assault weapon is a wobbler. Charged as a misdemeanor, it carries up to one year in county jail; as a felony, 16 months, two years, or three years. A narrow $500-fine exception exists for someone who lawfully owned the weapon before classification, has no prior convictions under the statute, is caught within one year after the registration period ended, and surrenders the firearm for destruction. That window is effectively closed for most weapons given how long ago the registration periods lapsed.9California Legislative Information. California Penal Code 30605
Manufacturing, selling, transporting into the state, or giving away an assault weapon is a straight felony punishable by four, six, or eight years in prison, with a one-year enhancement for transfers to a minor. Each weapon counts as a separate offense.10California Legislative Information. California Penal Code 30600
Since 2023, SB 1327 also lets any private person sue someone who violates the assault weapon ban. A successful plaintiff receives at least $10,000 in statutory damages per weapon, plus attorney’s fees. Criminal prosecution isn’t the only exposure.11California Legislative Information. SB 1327
Transporting a Compliant Rifle
Even with a fully compliant rifle, California controls how you move it. In a vehicle the rifle should be unloaded and stored in a locked container. A locked container means a fully enclosed, locked case; a car trunk qualifies, but a glove compartment or center console does not.
If you’re driving through California on the way elsewhere, 18 U.S.C. ยง 926A provides some protection. You may transport a firearm through any state if you can legally possess it at both origin and destination, the firearm is unloaded, and it’s not accessible from the passenger compartment; in vehicles without a separate trunk, it must be in a locked container.12Office of the Law Revision Counsel. 18 U.S. Code 926A – Interstate Transportation of Firearms That protection only covers passing through. Stop in California for anything beyond a brief travel-necessary stop and state law applies in full, and if the rifle itself is non-compliant under California standards, the federal transport rule won’t shield you from a state assault weapon charge.