California has approved a new firearm restriction aimed at a specific class of popular handguns that lawmakers say can be readily modified into fully automatic weapons. Governor Gavin Newsom signed Assembly Bill 1127 into law on October 10, enacting one of the state’s most targeted handgun bans to date.
The legislation, introduced by Assembly Members Jesse Gabriel of Encino and Catherine Stefani of San Francisco, prohibits the future sale of semi-automatic handguns designed in a way that allows them to be quickly and easily converted into fully automatic machine guns. Lawmakers focused particularly on handguns equipped with a “cruciform trigger bar,” a mechanism they say facilitates illegal modifications with minimal tools or parts. These modifications typically involve the installation of a small device, often referred to as a “switch,” that can transform the firearm’s function from semi-automatic—one round per trigger pull—to fully automatic, firing continuously as long as the trigger is held.
The ban applies to new sales within California and covers several widely sold models, including handguns manufactured by Glock. These models, and others with similar design features, have been identified by law enforcement agencies across the country as increasingly associated with illegal conversions. In recent years, federal and state authorities have reported a rise in the seizure of modified handguns equipped with conversion switches, some of which are 3D-printed or imported illegally.
Supporters of the new law argue that the growing availability of these switches has created a public safety gap that existing firearm regulations did not adequately address. By prohibiting the sale of handguns that are compatible with such devices, lawmakers intend to curb both the circulation of these specific weapons and the ability to convert them in the first place. The law does not confiscate handguns already owned by Californians, but it does restrict new sales going forward, effectively phasing these models out of the state’s retail market over time.
The measure reflects California’s continuing efforts to enact some of the strictest gun regulations in the United States. The state already requires background checks for all firearm and ammunition purchases, maintains a roster of approved handguns, and has enacted bans on assault weapons and large-capacity magazines. This new law adds another layer to that regulatory framework, focusing on the mechanical features of handguns rather than their appearance or capacity.
The legislation also aligns with ongoing federal enforcement efforts against conversion devices. The Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) classifies the switches as machine guns under federal law, making their possession illegal without special licensing. In California, possession of a fully automatic firearm or a conversion device carries severe criminal penalties.
By zeroing in on firearm design rather than modifications alone, state lawmakers are attempting to prevent the spread of easily convertible handguns at the point of sale, closing what they view as a loophole exploited by illegal gun traffickers and individuals seeking to bypass existing restrictions. The law is scheduled to take effect in the coming months, giving retailers time to adjust their inventories and comply with the new sales prohibition.