Imagine a device no larger than a quarter that, when attached to a Glock pistol, transforms it from a semi-automatic firearm into a fully automatic machine gun. Known as a “Glock switch,” this small attachment overrides the pistol’s standard firing mechanism, allowing it to discharge multiple rounds with a single trigger pull. The result is a weapon capable of firing at rates up to 1,200 rounds per minute, emptying a standard magazine in mere seconds.​

See below.

How Do They Work?

The device works by turning a regular semi-automatic Glock pistol into a fully automatic weapon — meaning the gun will keep firing as long as you hold the trigger down. It does this by interfering with the gun’s normal trigger mechanism.

In a standard Glock pistol, here’s what happens: You pull the trigger, the gun fires one shot, and then the trigger bar catches the firing pin. This action prevents the gun from firing again until you release the trigger, which resets everything for the next shot. That’s how most handguns work — one pull of the trigger equals one bullet fired.

But when a Glock switch is installed, everything changes. The switch replaces the backplate on the slide of the gun. Inside the switch is a tiny piece called a “disconnector.” This part presses against the trigger bar and stops it from resetting after each shot.

Every time the slide cycles — meaning the gun fires, the slide moves back, and a new round is loaded — the switch makes sure the firing pin is released again immediately without waiting for the trigger to reset. The result is fully automatic fire, and the Glock can empty an entire magazine in a matter of seconds.

Glock Switch

How Are Glock Switches Made?

Originally patented in 1996 by Venezuelan inventor Jorge A. Leon, the Glock switch has evolved from a niche accessory to a widely produced and distributed device. While some are manufactured overseas, particularly in China (of course), the advent of 3D printing has made it alarmingly easy for individuals to produce these switches at home. With access to a 3D printer and basic materials, one can fabricate a Glock switch for as little as $20.​ 

I should probably note right now that Glock, the Austrian firearms manufacturer, has no affiliation with the creation or production of these conversion devices and does not manufacture or endorse them. The only Glock model with a factory-built select-fire capability is the Glock 18, which is distinct from the aftermarket “Glock switch” and is not available to civilians.

I’ll bet Glock wishes they were called something else. They are sometimes referred to as “giggle switches” or auto sears.

Can They Be Used On Guns Other Than Glocks?

Here’s the deal — Glock switches were designed with one purpose in mind: turning Glock pistols into fully automatic weapons. They’re tailor-made to fit right onto the back of a Glock’s slide, replacing the small rear plate and taking advantage of Glock’s specific internal trigger and sear setup. In other words, these little monsters were built for Glocks and Glocks alone.

But this is America, where innovation often comes from the back of a garage or the corner of the internet. Many pistols on the market today are what folks call “Glock clones.” These are handguns from other manufacturers that copy Glock’s design down to the internal parts and removable backplate. Because of that, Glock switches can often fit these clones like a glove — giving criminals the same rapid-fire capability without the Glock brand name.

Now, can you slap a Glock switch onto just any pistol or rifle and turn it into a machine gun? Not exactly. Other firearms, like AR-15 rifles or different brands of semi-automatic pistols, need their own style of conversion devices. For AR-15s, for example, there are drop-in auto sears or lightning links that do a similar job — but they’re built specifically for that platform. Trying to force a Glock switch onto a SIG SAUER or a Smith & Wesson? Not going to happen unless that gun is a near-identical Glock copy.

Bottom line: Glock switches work best — and almost exclusively — on Glocks and guns designed like them. Other firearms need their own breed of illegal hardware to go full-auto. It’s a dark and growing underground world of weapon modification, and Glock switches are just one piece of the puzzle.

Legal Status: A Federal Offense

Under the National Firearms Act (NFA), Glock switches are classified as machine gun conversion devices. This designation makes their possession, manufacture, or distribution illegal for the vast majority of civilians in the United States. Violations can result in severe penalties, including up to 10 years in federal prison and fines reaching $250,000. Even possessing a non-functional or replica Glock switch can lead to prosecution, as the law does not differentiate based on the device’s operability.

The Proliferation and Its Consequences

The rise in Glock switch usage has not gone unnoticed. Law enforcement agencies across the country have reported a surge in crimes involving these devices. Between 2017 and 2021, the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) seized over 5,400 machine gun conversion devices, marking a 570% increase from the previous five years. In response, states like Alabama have enacted laws banning Glock switches, empowering local authorities to take action against their possession and distribution.

Use in Mass Shootings​

In recent years, Glock switches have been linked to a disturbing number of mass shootings across the United States. One of the most high-profile incidents occurred in Birmingham, Alabama, in September 2024. A shooting near the University of Alabama at Birmingham left four people dead and at least 17 others wounded. Investigators found over 100 shell casings at the scene, and police believe the attackers used handguns equipped with Glock switches. Local officials pointed to the case as a chilling example of how these devices can turn a street fight into a massacre.

Just two months later, in November 2024, another mass shooting took place in Tuskegee, Alabama. Again, authorities linked the violence to Glock switches, underscoring how common these modifications have become in high-casualty events. In this particular incident, one person was killed, and twelve others were injured by gunfire.

The problem isn’t confined to Alabama. In April 2022, a mass shooting in downtown Sacramento, California, also involved a Glock modified with a switch. That incident spurred efforts at both the state and federal levels to crack down on the manufacture and sale of these conversion devices.

There have been similar shootings in several other cities, including Fresno, California (November 2019); Chicago, Illinois (May and October 2022, and again in October 2023); Mobile, Alabama (December 2022); Dadeville, Alabama (April 2023); Boston, Massachusetts (August 2023); Philadelphia, Pennsylvania (March 2024); Memphis, Tennessee (April 2024); and Detroit, Michigan (June 2024). In each of these cases, Glock switches were either confirmed or strongly suspected to have been used, turning otherwise limited shootouts into deadly barrages.

Looking Forward

The right to keep and bear arms is a cornerstone of American freedom, but devices like the Glock switch likely were not designed with responsible gun owners in mind. These modifications turn common handguns into weapons that can potentially put innocent lives at risk and give anti-gun voices more ammunition than they need.

Keeping them out of the hands of criminals isn’t just a matter of law — it’s common sense for anyone who cares about preserving both safety and Second Amendment rights.

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Stay informed and vigilant. The landscape of firearm modifications is evolving rapidly, and understanding these changes is essential for ensuring safety and compliance with the law.