SIG P320 FRT: Reaper Fitment & Install Guide (M17, M18)

Despite the name, the Reaper is not a replacement trigger shoe. It is a single component that goes where your factory disconnector used to sit inside the fire control unit, and your existing trigger, trigger bar, and sear all go back in around it. The pistol still fires one round per deliberate trigger pull. What changes is who returns the trigger forward: instead of waiting for your finger to release, the gun uses its own cycling to push the trigger back through reset against your finger. Removing the human reset is the whole point, because on any fast string that is the slow link.

That slide-driven reset is why the setup section below matters more than the install. A forced reset trigger on a handgun is powered by slide velocity, so anything that slows the slide down or shortens its travel shows up first as an incomplete reset. On the P320 the two things that change slide behavior are the shorter Compact and Carry slides and any aftermarket or cut slide, which is exactly where the maker publishes a spring requirement. Which platforms have a forced reset path at all is mapped in our FRT compatible guns guide. The two closest handgun comparisons are our Glock FRT guide, where fitment turns on generation rather than model, and our Walther PDP reset lever guide, which runs into the same unpublished-fitment problem from the other direction.

Ignore the phrase drop-in trigger kit. The maker’s own video walkthrough is a full fire control unit teardown, and that is the most important thing to know before you order. You will need a bench block, a 3/32 inch punch, a 1/16 inch punch, and a hammer. The box holds one FRT component and two nylon spacers, one of which gets installed and one of which is a spare.

The first half of the job is factory procedure and needs no tools at all. SIG describes the fire control unit as the frame housing the trigger, sear, and slide catch lever, and the current P320 manual has a section for taking it out: pull the slide, rotate and pull the takedown lever outward together, push the unit forward, then lift the frame rails and rotate the unit up and out of the grip module. On a modular pistol that much is expected owner maintenance.

The second half is where the punches come in, and it belongs entirely to Texas Trigger USA. Its walkthrough strips the unit down, removing the trigger bar spring, trigger bar, slide catch, pins, sear housing, and the factory disconnector. Your existing trigger, trigger bar, sear, and lever safety then go back in, one nylon spacer fits to the sear housing, and the Reaper takes the position the disconnector used to occupy. Nothing is filed, cut, or drilled anywhere in the process, which is a genuine advantage over a fitted handgun reset device like the Walther A.R.T., whose install cuts a permanent notch into the trigger shoe.

Judge the finished install on outcomes you can check with an unloaded pistol and dummy rounds, before any live ammunition. The trigger returns completely forward every time. Every factory safety feature behaves exactly as it did before the work. Nothing binds through the full travel. Hand-cycle the slide and confirm all of it. Any hesitation in the return, any drag, or any change in how the safeties feel means the pistol goes back to the bench rather than to the firing line.

This is the section that decides whether your Reaper runs, and it is the part most owners skip. A brand-new P320 needs a break-in period before the trigger works as intended, and the maker puts it at roughly 400 to 600 rounds regardless of model. The reason given is mechanical rather than vague: a factory coating inside the gun wears down and friction drops, and Texas Trigger USA notes that this lines up with SIG Sauer’s own factory break-in period for the platform. A pistol that is already well broken in does not need it. Budget for the written figure rather than the lower number the install video quotes near its close. If you would rather not buy 600 rounds to find out, the maker allows dry-cycling with the trigger held back, which works the same surfaces that break in during live fire.

Ammunition is the cheap variable. The maker recommends 115 to 124 grain, leaning on the heavier end while the gun is still tight and dropping to 115 grain once it is broken in, and names Blazer Brass full metal jacket round nose as its preference. Nothing exotic is required, which is the point: a forced reset trigger needs consistent slide velocity more than it needs premium ammunition.

CCI Blazer Brass 9mm 115gr FMJ

The maker's named break-in load, at the 115 grain weight it recommends for a broken-in pistol

$12.99

The most popular budget brass-cased 9mm range ammo in America. Consistent, affordable, reloadable, and available everywhere. The round that most pistol shooters have fired more than any other.

115 grain FMJ9mm Luger1,145 fps muzzle velocity323 ft-lbs energy

Pros

• +Strong value brass-cased 9mm when bulk pricing is available
• +CCI primers provide exceptional ignition consistency
• +Reloadable brass cases with Boxer primers

Cons

• −Slightly lower velocity than Federal American Eagle
• −Not the most accurate training round available
• −Packaging can vary between production runs

Caliber: 9mm LugerBullet Weight: 115 grainBullet Type: Full Metal Jacket (FMJ)Muzzle Velocity: 1,145 fps (4" barrel)

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Break-in is measured in hundreds of rounds, so buy it by the case rather than the box. Our 9mm range ammunition guide compares the other brass-cased training loads worth standardizing on if you would rather buy in bulk than by brand.

Spring weight is where the host list turns into a shopping list. The maker states that OEM Compact and Carry pistols may need a 14 lb recoil spring in place of the factory spring, along with a compatible guide rod assembly, and that this requirement applies to no OEM model other than those two. An aftermarket or slide-cut slide also needs a guide rod assembly and a spring, and there the weight varies by slide, typically 14 to 18 lb. Budget the spring and guide rod into the purchase if you own a Compact, a Carry, or a cut slide, because the trigger alone will not be the whole bill.

Before you order, find out which fire control unit you own. SIG Sauer has run a Voluntary Upgrade Program for earlier P320 pistols since August 2017, and the upgraded design is not a cosmetic revision: it uses a thinner, lower-mass trigger together with lighter sear and striker components, and it adds a mechanical disconnector. SIG encourages owners whose pistols do not have the upgraded design to use the program, which is free.

That matters more here than on any other host, because the disconnector is the exact part the Reaper displaces. The install takes the factory disconnector out and puts the Reaper in its place, and a mechanical disconnector is one of the things the upgrade program added. Texas Trigger USA does not say whether the Reaper is built for the original fire control unit, the upgraded one, or both, and its silence covers the product page, the installation walkthrough, and its contact pages alike. So if your P320 predates the program, establish its upgrade status with SIG first and confirm Reaper compatibility with Texas Trigger USA second. Two questions answered in advance beat a trigger that half works in a fire control unit nobody specified.

Federally it is a grayer purchase than a rifle FRT, and sixteen jurisdictions ban, restrict, or leave it legally ambiguous. The National Firearms Act reaches a weapon that fires more than one round per single function of the trigger, and a forced reset trigger is built to fire exactly one, which is why these sell as ordinary parts rather than registered NFA items. That is a mechanism point rather than a closed federal question for a handgun. The Department of Justice’s May 2025 settlement with Rare Breed conditions its non-enforcement on the device not being designed for or used in a handgun whose magazine loads into the trigger-hand grip, and the announcement describes Rare Breed agreeing not to develop or design forced reset triggers for pistols. A P320 loads into the trigger hand, which puts the Reaper outside the settled rifle lane and into the same grayer position as other grip-fed handgun reset devices. Buy with that understood, and get current legal advice for your own situation.

State law operates independently of federal classification. Sixteen jurisdictions restrict forced reset triggers or rapid-fire activators: California, Colorado, Connecticut, Delaware, Florida, Hawaii, Illinois, Maryland, Massachusetts, Minnesota, Nevada, New Jersey, New York, Oregon, Rhode Island, and Washington D.C. Florida is legally ambiguous rather than a named ban, and Connecticut is ambiguous today with an express prohibition arriving October 1, 2026. Washington state does not ban forced reset triggers, though Texas Trigger USA declines to ship there anyway. Check the current status for your state in our state legality tool before ordering, because a vendor ship-to list is a shipping policy, not a legal opinion.