Installing your AIM SSTAT Trigger is a relatively simple process that should take approximately 10 minutes. We’ve demonstrated the process on a standard forged receiver with a milspec trigger. Steps 3 and 4 will vary if you have another drop-in or cassette-style trigger installed. In that case, you will remove it after step 2 and proceed with step 5.
You will need safety glasses, a brass or nonmetal punch (smaller than .154″), a hammer (we recommend a ball-peen hammer), 5/64 Allen wrench, flathead screwdriver (type of screwdriver may differ depending on rifle manufacturer’s grip screw).
Make sure the weapon is clear and there is not a round in the chamber. Remove the upper receiver from the weapon system.
Loosen the grip screw on the inside of the grip and remove it. It may be a flathead, torx head, or hex head, depending on the manufacturer. Carefully remove the grip to expose the spring inside. There is a detent behind the spring. Both of these are small and easily lost. Remove the spring and detent, using your hand or a plastic bin to catch the detent as it falls. Save them for reinstallation (Step 7).
With a small brass punch or nonmetallic item (to avoid damage to the finish), press out the hammer pin and remove the hammer and hammer spring.
Next, press out the trigger pin. This may require pressing down on the disconnector. Remove the disconnector, disconnector spring, trigger, and trigger spring. Now remove the safety selector if it did not come out earlier. The pocket that everything was in should now be clear and empty.
Drop the AIM SSTAT trigger in the pocket using the holes as a reference for direction. The hammer will face the magwell.
Install KNS pins by following the instructions on the KNS package (or install your standard pins if you don’t have KNS pins). Make sure the KNS screws are snug, not torqued.
Reinstall the safety selector and the grip assembly with the detent, detent spring, grip, and grip screw to their respective positions in that order.
There are two small setscrews located on the trigger system under the hammer springs. Lift or shift over each hammer spring and use a 5/64 Allen wrench to snug the setscrews to the floor of the receiver. Do not overtighten, as this will change the poundage of the trigger. This step is necessary for the weapon to function properly.
DO NOT TIGHTEN OR LOOSEN THE MAIN SETSCREW (LOCATED IN THE CENTER). THIS HAS ANOTHER FUNCTION AND IS NOT TO BE CHANGED BY THE OPERATOR. SEEK A COMPETENT GUNSMITH IF CHANGES NEED TO BE MADE.
Perform a functions check on the weapon to verify correct installation.
Enjoy your AIM SSTAT trigger!