PC 16740:
Imitation Firearm Definition

California Penal Code Section 16740^[1] defines "large-capacity magazine" for purposes of California's restrictions on such devices. This definition is central to prosecutions under Penal Code Sections 32310 through 32390, which prohibit the manufacture, importation, sale, and possession of large-capacity magazines.

Statutory Definition

A "large-capacity magazine" is any ammunition feeding device with the capacity to accept more than 10 rounds, any ammunition feeding device that can be readily restored or converted to accept more than 10 rounds, or any combination of parts from which an ammunition feeding device capable of accepting more than 10 rounds can be assembled.

Semiautomatic Pistol Capacity Exception

The definition also includes any ammunition feeding device that is designed and intended for use with a semiautomatic pistol and that can accept more than 10 rounds when used in a semiautomatic rifle. This provision targets pistol-caliber carbines where a pistol magazine with a capacity greater than 10 rounds is used in a rifle platform.

Tubular Magazine Exception

An attached tubular magazine designed to accept, and capable of operating only with, .22 caliber rimfire ammunition is excluded from the definition of large-capacity magazine. This exception preserves the legality of lever-action and tube-fed .22 rifles and pistols that are inherently limited to rimfire cartridges.

Readily Convertible Standard

The phrase "readily restored or converted" has been the subject of litigation. Courts have generally held that a magazine that can be modified to exceed 10-round capacity with commonly available tools or components in a short amount of time qualifies under the definition, even if not currently configured to do so.

Relationship to Section 32310

PC 16740 supplies the definition used throughout Division 10 of Title 4 of Part 6 of the Penal Code, which governs large-capacity magazines. Penal Code Section 32310 prohibits manufacturing, importing, selling, giving, or lending any large-capacity magazine, with limited exceptions for law enforcement and pre-ban grandfathered magazines (though the grandfathering provision has been the subject of ongoing litigation in Duncan v. Bonta).