Last Updated on October 13, 2025 by The HD Post Staff

CALIFORNIA — Governor Gavin Newsom signed Assembly Bill 1127 on October 11, banning the sale, transfer, possession, and manufacture of machinegun-convertible pistols — semi-automatic handguns that can be readily modified into fully automatic weapons using a small device known as a “switch.”

Assemblymembers Jesse Gabriel and Catherine Stefani, who co-authored the bill, argue that AB 1127 closes a significant loophole that allows dangerous weapons to be easily created from legally sold pistols.

Starting January 1, 2026, licensed firearms dealers will be prohibited from selling or transferring these weapons, with escalating penalties for violations, including fines and license revocation.

784% increase in recoveries of illegal conversion devices

Fully automatic machine guns are lethal weapons capable of firing hundreds of rounds per minute. Some semi-automatic firearms include a design element that allows for a conversion to a fully automatic weapon with the use of a “switch.”

According to the ATF, recoveries of illegal conversion devices used to turn semi-automatic guns into machine guns rose 784%—from 658 in 2019 to 5,816 in 2023.

The law expands the existing definition of “machine gun” under Penal Code to include these convertible pistols, making their manufacture, sale, or possession a felony.

AB 1127 exempts law enforcement, allowing sales to police, sheriff’s offices, prosecutors, the Highway Patrol, the Department of Justice, Corrections and Rehabilitation, and the military for official use.

Critics say the law erodes Second Amendment rights

The bill passed with votes of 54-16 in the Assembly and 29-9 in the Senate.

Critics argue that by redefining semi-automatic pistols as “convertible” because they could be modified sets a dangerous precedent for future gun bans and further erosion of Second Amendment rights.

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