New Mexico – police and prosecutors backed an effort to outlaw devices that convert pistols into machine guns. In Alabama, the governor made it a priority.
Lawmakers in both states — one led by Democrats, the other by Republicans—responded this year with new laws making so-called Glock switches illegal.
At least half of U.S. states now have similar laws prohibiting the possession of such devices, a list that has grown over the past decade as law enforcement officers have found more of the tiny yet powerful devices attached to guns.
States are mimicking federal law, which for for decades has generally prohibited machine guns and any parts that can transform semiautomatic weapons into automatic ones.
What does federal law say?
A machine gun is defined by US law as a weapon that fires multiple shots with a single trigger pull. The definition also includes any components used to convert a weapon into a machine gun.
Federal law prohibits the possession of machine guns manufactured after 1986, with some exceptions for law enforcement, the military, and certain licensed dealers. Almost all conversion devices are illegal because they were manufactured recently.
Those convicted of possessing machine guns and conversion devices face up to ten years in prison.
What is a Glock switch?
Glock switches are one type of machine gun conversion device. It is a metal or plastic piece the size of a coin that attaches to the back of a Glock pistol, a popular brand among both cops and criminals. The switch interferes with a gun’s internal trigger components, causing it to fire continuously when the trigger is pulled back and held.
A gun with a switch can fire dozens of bullets in seconds, much like a factory-made machine gun.
Other brands of Glock-style pistols can also be converted into machine guns. Some semiautomatic rifles are also capable of this. Such conversion devices are also known as auto sears, selector switches, or chips.
What does the data indicate?
The use of auto sears spiked in the past decade, partly because they can be made inexpensively with 3D printers.
From 2012 to 2016, just 814 machine gun conversion parts were taken into custody by the Bureau of Alcohol, Tobacco, Firearms and Explosives. That swelled to 5,454 from 2017-2021.
In January, former President Joe Biden’s administration said 12,360 suspected machine gun conversion devices had been recovered in the U.S. and submitted to the ATF during a roughly 34-month period ending in October 2024.
Five states including Florida, Illinois, Texas, Montana and North Dakota accounted for nearly half that total.
What have states been doing?
Alabama is the latest state to ban Glock handguns. Republican Gov. Kay Ivey signed legislation this month that makes possessing parts designed to convert pistols into machine guns a felony punishable by up to ten years in prison.
The bipartisan effort in Alabama came after police said they suspected conversion devices were used in fatal shootings, including one in September that killed four and injured 17 outside a Birmingham lounge.
Democratic New Mexico Gov. Michelle Lujan Grisham signed legislation in February making the possession of a weapon conversion device a felony punishable by up to three years in prison.
Similar legislation passed the New Jersey General Assembly last week and is now headed to the Senate. Bills are also pending in other states.
Last year, Republican Virginia Gov. Glenn Youngkin signed legislation making auto sears illegal. However, Youngkin vetoed legislation this week that would have broadened the existing ban on “trigger activators” to include additional devices that increase the firing rate of semiautomatic weapons.
What do gun control advocates want?
Groups such as Everytown for Gun Safety say state laws provide a sometimes easier alternative to federal prosecution for possessing Glock switches. But they want to go further.
Everytown for Gun Safety is backing legislation in California, Maryland and New York that would make it illegal to sell pistols that could be transformed into machine guns.
“That really puts the pressure where it belongs — on the manufactures that are making money off of guns that they know can be readily turned into machine guns,” said Nick Suplina, senior vice president for law and policy at Everytown for Gun Safety.
Several cities and states including Baltimore, Chicago, Minnesota and New Jersey have sued Glock for making pistols that can be converted by others to automatic weapons.
What do gun-rights groups say?
The National Rifle Association points out that US attorneys can already prosecute people for misusing gun conversion devices without the need for state laws.
Another gun-rights organization, Gun Owners of America, believes people should have the Second Amendment right to own machine guns. State laws prohibiting machine gun conversation devices are “duplicative” and “pure virtue signaling,” according to Aidan Johnston, federal affairs director for Gun Owners of America.
He stated that guns that can fire automatically can be useful in situations such as eradicating large groups of feral hogs that are destroying land.
“Just because you put that on your firearm does not mean that you are a violent criminal or that you necessarily are a dangerous person,” Johnston told the crowd.
