Glock Switch vs. FRT: A Direct Comparison of Two Trigger Systems

You’re at the bench, looking to increase your Glock’s rate of fire. Two terms dominate the conversation: the Glock auto sear (commonly called a “switch”) and the Forced Reset Trigger (FRT). One is a simple metal component that replaces your rear plate, the other is a complex drop-in trigger assembly. The functional difference is stark, and choosing the wrong one for your application is a costly mistake. Let’s break down the mechanics, legality, and real-world performance so you can make an informed decision.

Mechanical Operation: How They Actually Work

A Glock switch is a small, precisely machined auto sear that installs into the rear cavity of your slide, replacing the back plate. Its job is purely mechanical: it intercepts the trigger bar’s reset, forcing the striker to release with every rearward movement of the slide. This creates a true automatic firing cycle for as long as you hold the trigger back. An FRT-15 or similar FRT for a Glock, like the Rare Breed FRT-9, operates on a different principle. It’s a complete trigger shoe and mechanism that uses a proprietary disconnector and spring system to “force” the trigger to reset the instant the bolt or slide closes, allowing for an extremely rapid simulated rate of fire. The key distinction? The switch provides automatic fire; the FRT facilitates a blisteringly fast, but technically semi-automatic, pull for every shot.

Rate of Fire and Practical Performance

On the range, the difference is dramatic. A properly installed Glock switch, like the common “Glock 17/19” style auto sear, will yield a consistent rate of fire between 1,200 and 1,400 rounds per minute, emptying a standard 17-round magazine in under a second. Control is challenging and ammo consumption is extreme. An FRT system’s performance is entirely dependent on your finger speed and technique. A skilled shooter can achieve rates that feel nearly automatic—perhaps 600-800 rounds per minute—but each shot still requires a distinct trigger pull and release. For sustained rapid fire, the switch is unbeatable. For high-speed semi-auto drills where maintaining legal compliance is paramount, an FRT is the engineered solution. We stock tested and reliable components for both approaches at Glockswitchstore.

Installation Complexity and Reliability

Installation is where these systems diverge completely. A Glock switch requires detailed disassembly of your slide. You must drive out the striker sleeve, remove the factory back plate, and install the auto sear and its spring correctly. It’s a 10-minute job with the right tools and know-how, but improper installation leads to immediate failures. FRT units are typically drop-in assemblies. For a Glock platform, you’d replace the entire trigger mechanism housing. It’s simpler but often requires specific fitting or tuning to ensure the forced reset function works reliably across different generations and models. Reliability favors simplicity: a well-machined switch has fewer moving parts to fail. However, an FRT’s complexity means it can be finicky with aftermarket connectors or out-of-spec frames.

The Critical Legal Distinction

This is the most important section. Under the National Firearms Act (NFA), a machine gun is defined as any weapon which shoots more than one shot, without manual reloading, by a single function of the trigger. A Glock switch meets this definition precisely—one pull, continuous fire. Mere possession of an unregistered auto sear is a federal felony. An FRT-15 trigger was declared a machine gun by the ATF in 2022, and similar rulings have followed for pistol variants. While the FRT mechanism requires a separate trigger pull for each round, the ATF contends its design allows the firearm to “function automatically.” As of this writing, possession of an FRT is legally fraught. You must consult current federal regulations and potentially seek a manufacturer’s determination letter before acquisition. We provide informational resources to responsible buyers at Glockswitchstore.

Choosing for Your Application

Your choice boils down to intended use and legal risk tolerance. If you are an SOT holder building registered post-sample machine guns for demonstration or law enforcement, the Glock switch is the standard, professional component. Its purpose is unambiguous. For the civilian enthusiast operating within a strict interpretation of the law, the legal path for either system is currently extremely narrow. It’s crucial to understand that products like the Auto Key Card or certain “lightning link” designs for AR platforms fall into the same legal category as a switch. There is no legal shortcut to automatic fire. Your due diligence is non-negotiable. For components and informational clarity, our store is a resource built on technical specifics, not legal advice.

What is a switch for a Glock?

A Glock switch is the common term for an auto sear, a small metal component that replaces the rear plate on a Glock slide. When installed, it mechanically converts the pistol from semi-automatic to fully automatic fire, releasing the striker with each cycle of the slide as long as the trigger is depressed.

Is an FRT trigger considered a machine gun?

As of March 2026, the ATF classifies Forced Reset Triggers (FRTs) like the FRT-15 and FRT-9 as machine guns under the National Firearms Act. This determination is based on the ATF’s evaluation that the trigger’s design allows the firearm to “function automatically,” despite requiring separate trigger pressure for each shot.

Can you legally own a Glock switch?

You can only legally possess a Glock auto sear if it is registered in the National Firearms Act (NFA) registry before May 1986 (making it a transferable “pre-86” machine gun) or if you are a licensed manufacturer (SOT) with authorization to build post-86 samples for official use. Unregistered possession is a federal felony.

Which is more reliable, a switch or an FRT?

Mechanically, a well-made Glock switch is often more reliable due to its extreme simplicity—it’s just a sear and a spring. FRT mechanisms have more internal parts and springs that must interact perfectly with your specific firearm, making them more susceptible to tuning issues and malfunctions if not fitted correctly.

Understanding the mechanical and legal nuances between these systems is essential. For those with the proper licensing or who are conducting technical research, you can browse our glock switches collection and related components, all sourced for precision and reliability.

Last updated: March 25, 2026