What a force reset trigger does

A force reset trigger (FRT) is a type of AR-15 trigger that uses a spring-loaded hammer to reset itself after each shot without you having to release the trigger. On a standard trigger, you pull and release to fire each round. With an FRT, you can keep your finger on the trigger and let the hammer spring forward on its own, firing the next round when the bolt chambers it.

The mechanism works because the trigger group includes a secondary spring that pushes the hammer back into firing position while your finger stays pressed. This creates a rapid-fire effect without the shooter having to move their finger. The trigger itself does not move back to its resting position — only the hammer resets.

FRTs became popular because they can produce firing rates similar to a semi-automatic rifle modified to function like a fully automatic weapon, but the rifle itself remains semi-automatic in design. This distinction matters legally, because the legality of FRTs has been contested in federal courts and varies by jurisdiction.

Key Takeaways

  • A force reset trigger uses a spring to reset the hammer while your finger stays on the trigger, allowing rapid fire without finger movement.
  • The ATF has taken different positions on FRT legality, and some federal courts have ruled them illegal as machine gun conversions while others have not.
  • Several states have banned FRTs outright, while others have no specific restriction; you are responsible for knowing your local and state laws before purchasing or installing one.
  • Installing an FRT requires removing the standard trigger group and replacing it with the FRT assembly, a process that takes basic gunsmithing knowledge.
  • FRTs are not the same as bump stocks or other rapid-fire devices, though they produce similar firing rates and face similar legal scrutiny.

How the internal mechanism resets the hammer

The force reset trigger works through a specific arrangement of springs and levers inside the trigger group. When you fire a shot, the hammer strikes the firing pin and moves forward. At the same time, a secondary spring — separate from the main trigger spring — begins pushing the hammer back toward the cocked position.

As the bolt cycles and chambers the next round, the hammer reaches its fully cocked position again. If your finger is still pressing the trigger, the hammer can when ready strike the firing pin once more. The trigger itself never returns to its resting state; only the hammer moves. This is the key difference from a standard trigger, where the entire trigger group must reset before the next shot fires.

Different manufacturers design their FRTs with slightly different spring tensions and lever geometries, which affects how reliably the reset occurs and how fast the firing rate becomes. Some designs reset faster than others, and some are more prone to malfunctions if the rifle is not perfectly clean or if ammunition is underpowered.

Legal status and why it remains unclear

The legal standing of force reset triggers in federal law is unsettled. The ATF (Bureau of Alcohol, Tobacco, Firearms and Explosives) has issued multiple positions on FRTs over the past several years, sometimes declaring them legal and sometimes declaring them illegal as machine gun conversions. This inconsistency has led to lawsuits, and different federal courts have ruled differently on whether an FRT converts a semi-automatic rifle into a machine gun under the law.

In 2024, a federal judge in Texas ruled that certain FRT designs do not meet the legal definition of a machine gun, while other courts have reached the opposite conclusion. The Supreme Court has not yet ruled on the question. Because of this uncertainty, some retailers have stopped selling FRTs, and some manufacturers have paused production.

Your responsibility is to know the laws in your state and locality before you purchase or install an FRT. Several states, including California, have banned FRTs by name in state law, making them illegal to own regardless of federal court rulings. Other states have no specific restriction. Federal law also applies, so you must follow whichever rule is stricter in your location.

State and local restrictions you should know about

California explicitly bans force reset triggers under state law. New York has also restricted them. Some other states have broader bans on devices that increase firing rate, which may or may not include FRTs depending on how the law is written and how prosecutors interpret it. A few states have no specific mention of FRTs in their firearms laws.

Because the legal landscape changes and varies widely, you should contact your state's fish and wildlife department or attorney general's office to ask about FRT legality in your state before purchasing one. Local city or county ordinances may also restrict them even if state law does not. Many gun ranges also have their own policies on what trigger types are permitted on their property.

How to install a force reset trigger

Installing an FRT requires removing your rifle's standard trigger group and replacing it with the FRT assembly. The process is similar to installing any aftermarket trigger, but it does require some mechanical knowledge and the right tools.

First, may support the rifle is unloaded and the safety is on. Remove the pistol grip by unscrewing the grip screw on the lower receiver. Once the grip is off, you can access the trigger group. Push out the trigger pin and hammer pin using a punch tool, then remove the standard trigger assembly. Insert the FRT assembly in the same location, align the pins, and tap them back through. Reinstall the pistol grip and screw it tight.

After installation, test the trigger function with the rifle unloaded. Press the trigger and listen for the hammer reset. If the reset does not occur smoothly or if the hammer does not stay cocked, the FRT may not be seated correctly or may be incompatible with your lower receiver. Some lower receivers have slight variations that can affect FRT function.

How FRTs differ from bump stocks and other rapid-fire devices

A bump stock is a different device that attaches to the outside of the rifle's stock and uses recoil to move the rifle forward and backward, causing your finger to strike the trigger repeatedly. Bump stocks are federally banned as of 2019. Force reset triggers work internally through the trigger mechanism itself, not through recoil manipulation.

Another device called a hellfire trigger or binary trigger fires once when you pull the trigger and once when you release it, effectively doubling your firing rate. Binary triggers are legal in most states but are also subject to legal challenge in some jurisdictions. FRTs and binary triggers are not the same, though both produce rapid fire.

The practical result of all three devices is similar — faster firing than a standard semi-automatic trigger — but the mechanism is different in each case. This distinction matters legally because the law defines machine guns by how they function, not by how fast they fire. A device that is legal or illegal depends on whether it meets the technical definition in your jurisdiction's law.

Reliability and maintenance concerns with FRTs

Force reset triggers are generally reliable when properly installed and maintained, but they are more complex than standard triggers and require more attention to cleanliness. The secondary spring that resets the hammer can stick or fail to reset if dirt or powder residue builds up inside the trigger group. Regular cleaning is more important with an FRT than with a standard trigger.

Some shooters report that FRTs are sensitive to ammunition quality. Underpowered or low-velocity rounds may not cycle the bolt hard enough to fully chamber the next round, which can cause the hammer to reset but the rifle to fail to fire. This is not a defect in the FRT itself but rather a mismatch between the trigger design and the ammunition being used.

If you install an FRT, you should clean your rifle more frequently than you would with a standard trigger, especially after high-round-count shooting sessions. Keep the trigger group dry and free of debris. If the reset becomes sluggish or unreliable, disassemble the trigger group and inspect the secondary spring for damage or contamination.

Frequently Asked Questions

Is a force reset trigger the same as a fully automatic rifle?

No. A fully automatic rifle fires continuously as long as you hold the trigger. An FRT fires one round per hammer reset, which happens when the bolt chambers the next round. The rifle is still semi-automatic in design. However, the legal question of whether an FRT illegally converts a semi-automatic rifle into a machine gun is currently disputed in federal courts.

Can I legally own an FRT in my state?

That depends on your state and local laws. California and New York have explicit bans. Other states may have broader restrictions on rapid-fire devices. You should contact your state attorney general or fish and wildlife department to confirm the law in your location before purchasing or installing one.

Will an FRT work in any AR-15 lower receiver?

Most FRTs work in standard AR-15 lower receivers, but some lower receivers have slight variations in dimensions or tolerances that can affect fit and function. Before installation, check the FRT manufacturer's compatibility list for your specific lower receiver model. If the FRT does not reset smoothly after installation, the lower may be incompatible.

What happens if I install an FRT in a state where it is banned?

Possessing a banned FRT can result in criminal charges, confiscation of the rifle, fines, and potential jail time depending on your state's penalties. The severity varies by state. You are responsible for knowing your local law before purchasing or installing one.

How does an FRT affect the accuracy of my rifle?

An FRT does not inherently affect accuracy. However, because the trigger itself does not reset, the trigger pull feel is different from a standard trigger. Some shooters find this different feel affects their ability to shoot precisely, while others adapt quickly. The best way to know is to test one at a range if it is legal in your area.