The Rimfire Loophole:
Why Your 10/22 Isn't an Assault Weapon

Can I put a pistol grip stock on my Ruger 10/22 in California?

The Centerfire Limitation

California Penal Code Section 30515(a)(1)^[1] defines "assault weapon" in relevant part as a "semiautomatic, centerfire rifle" that does not have a fixed magazine and has any of the enumerated features (pistol grip, thumbhole stock, folding/telescoping stock, grenade/flare launcher, flash suppressor, forward pistol grip). The word "centerfire" is a critical limitation.

A semiautomatic rimfire rifle, such as the ubiquitous Ruger 10/22 (.22 LR), is not covered by the features test. This means a 10/22 with a detachable magazine, pistol grip stock, folding stock, and a flash suppressor is not an assault weapon under Section 30515(a)(1). This is not a loophole discovered by creative lawyers; the legislature deliberately limited the features test to centerfire rifles.

Important Limitations

The named-model ban still applies. Penal Code Section 30510^[2] incorporates the Roberti-Roos list by reference. A firearm covered by the named-model ban remains an assault weapon even if it does not meet the separate features test. The Ruger 10/22 is not on the Roberti-Roos named list.

Large-capacity magazine restrictions apply independently. Subject to its statutory exceptions, Penal Code Section 32310 prohibits possession of large-capacity magazines. The definition excludes permanently reduced devices, .22 caliber tube feeding devices, and tubular magazines in lever-action firearms. A 25-round Ruger BX-25 magazine is restricted under Section 32310 even though the rifle it fits is not an assault weapon. (Subject to ongoing Duncan v. Bonta litigation and Freedom Week acquisition arguments.)

Semiautomatic pistols and shotguns have their own rules. Section 30515(a)(4) covers semiautomatic pistols without fixed magazines that have a listed feature. Section 30515(a)(5) covers semiautomatic pistols with fixed magazines holding more than 10 rounds. Neither pistol provision has a centerfire limitation. Sections 30515(a)(6) and (7) cover semiautomatic shotguns. The rimfire gap applies specifically to the rifle features test.

Why This Matters

The rimfire exemption has practical significance for several popular platforms:

The Ruger 10/22 with a 10-round magazine and an AR-15-style chassis with a pistol grip and telescoping stock does not meet the centerfire rifle features test in Section 30515(a)(1). The Smith & Wesson M&P 15-22 (.22 LR), which closely resembles an AR-15, is not an assault weapon despite having a pistol grip and detachable magazine because it is rimfire. The Kel-Tec CP33 is a .22 LR pistol supplied with a 33-round magazine, which is subject to the large-capacity magazine restrictions. Section 30515(a)(4) has no centerfire limitation and covers a semiautomatic pistol without a fixed magazine that has a threaded barrel capable of accepting a flash suppressor, forward handgrip, or silencer.

Legislative Risk

In 2013, SB 374 proposed banning any semiautomatic rifle with a detachable magazine. Governor Brown vetoed it on October 11, 2013. The current features test in Section 30515(a)(1) applies to semiautomatic centerfire rifles.

Bottom Line

Settled: The features test in Section 30515(a)(1) applies only to semiautomatic centerfire rifles. Rimfire rifles may have any combination of features without triggering assault weapon classification under this subsection.

Unsettled: Whether the legislature will extend the features test to rimfire in future sessions. Whether certain rimfire platforms configured to closely resemble centerfire assault weapons could be challenged under other legal theories.

Do: Before configuring a rimfire rifle with features, verify that the specific model is not on the Roberti-Roos named list (Section 30510). Use only 10-round or smaller magazines unless you have a valid Freedom Week claim.