You’re here because you know what this is. This isn’t a toy or a novelty. It’s a precision-machined auto sear, commonly called a Glock switch. This small component replaces your factory rear slide plate and alters the firearm’s firing sequence. The result is a sustained cyclic rate for as long as the trigger is depressed. Let’s be clear about what you’re getting.

What This Is and What It Isn’t

This is a mechanical part. It’s a block of metal, precisely cut to specific dimensions. It is not a magical device. It doesn’t add horsepower or improve accuracy. Its sole function is to interrupt the standard reset of your Glock’s trigger mechanism.

When installed, it allows the pistol to cycle continuously. This places the firearm into a category of regulated items under the National Firearms Act (NFA). It is your responsibility, the end user, to understand and comply with all federal, state, and local laws regarding the possession and registration of such devices. Period.

We sell a component. We do not provide legal advice.

How It Works: No Secrets, Just Mechanics

Your Glock is a recoil-operated, semi-automatic pistol. After each shot, the slide cycles rearward, cocks the striker, and resets the trigger. The trigger must be released and pulled again to fire the next round.

This auto sear changes that. It sits in the channel where the slide’s backplate was. As the slide reciprocates, this component physically blocks the trigger bar from fully resetting. With the trigger held rearward, the disconnector cannot engage, and the striker releases the instant the slide returns to battery. This creates an automatic cycle until ammunition is expended or pressure on the trigger is released.

Important Note: Glock pistols are not designed for sustained automatic fire. Expect increased wear on components, rapid ammunition consumption, and significantly reduced control. This is a mechanical fact, not an opinion.

Installation: A 90-Second Procedure

If you can field-strip your Glock, you can install this. You won’t need a dremel, a hammer, or any special tools. Just a punch to drive out the slide’s backplate pin.

1. Clear and safe the firearm. Remove the magazine and visually inspect the chamber.
2. Pull the trigger to decock (on an empty chamber). Lock the slide rearward.
3. Use a punch to push out the rear slide plate pin. Remove the factory backplate.
4. Insert the auto sear into the same channel, ensuring it sits flush and the selector moves freely.
5. Re-insert the pin to secure it. That’s it.

The installation is reversible. Remove the part and reinstall your factory backplate to return the pistol to its original semi-automatic function. No permanent alteration is made to the firearm itself.

Compatibility & Quality

Our sear is machined from tool steel and heat-treated for durability. It’s designed to OEM Glock specifications for fit. It will work in Gen 3, 4, and 5 models (9mm, .40, .357 Sig) with standard factory slides. Fitment on aftermarket or heavily modified slides (Zev, Grey Ghost, etc.) may require minor fitting—this is the nature of non-OEM tolerances.

It is also compatible with Polymer80 and similar frames built to Glock specification. If your build uses a standard Glock-style slide and parts kit, it should function.

This part is not compatible with .45 ACP or 10mm Glock models (Glock 21, 41, 20, 40) due to different slide dimensions.

What You Need to Know Before You Buy

• Legality: This device is considered a machinegun under U.S. federal law (26 U.S.C. § 5845(b)). Possession without proper registration with the ATF and payment of the corresponding tax is a felony. It is the buyer’s sole responsibility to ensure compliance.
• Performance: As stated, automatic fire increases wear, reduces control, and drains ammo. It is mechanically harder on your pistol.
• Shipping: All orders ship in plain, unmarked packaging via expedited courier. No external indications of contents are present.
• Our Role: AutoGlockSwitch.com is a supplier of components. We manufacture and ship the part. The legal onus for registration, possession, and use rests entirely with the purchaser.

Frequently Asked Questions