The CMC trigger is a self-contained, one-piece design that makes drop-in installation easy. But if you feel uncomfortable performing installation yourself, or you lack the proper tools, seek out help from a gunsmith. Your trigger will come with instructions for installation.
Included in the CMC AR-15/AR-10 trigger package, you will find:
- Trigger assembly
- Two trigger pins
- Four small screws
- T10 Torx key
- Installation and maintenance instructions
To install the trigger, you will need:
- A screwdriver or appropriate tool to remove your grip from the lower receiver
- A light hammer and 1/8” punch
- The included T10 Torx key
- Low strength threadlocking compound such as purple Loctite (recommended)
- Degreasing agent such as denatured alcohol (recommended)
- Small patches and pipe cleaner to degrease hardware (recommended)
Ensure the firearm is unloaded before proceeding!
1. Thoroughly degrease the screws using the small patches and denatured alcohol. Degrease the threaded portions inside the pins using the pipe cleaner and denatured alcohol. This will help ensure the thread-locking compound will bond to the surface. Set aside pins to allow any remaining alcohol evaporate.
2. Separate the upper receiver of the AR from the lower receiver. Place the lower in a vise block if you have one to make installation easier.
3. Move the safety selector to the fire position.
4. While holding the hammer, depress the trigger. Slowly ease the hammer forward. Do not allow the hammer to drop on its own.
5. Use the punch and hammer to push out the upper trigger pin using a moderate amount of force.
6. Lift out and remove the hammer.
7. While pushing down on the disconnector, use the punch to drift out the second trigger pin.
8. Lift the trigger and disconnector out of the lower receiver.
9. Depending on the lower receiver, you may need to loosen the grip to remove the safety before you can replace the trigger. To do this, use the screwdriver or appropriate tool to release the fastener inside your grip, loosing the screw to allow the grip to lower down only about a quarter-inch. You will see a small spring exposed. The spring goes into the lower receiver and puts pressure on a small detent that holds the safety selector in place. With the pressure relieved, remove the safety selector from the lower receiver.
10. Cock the hammer of your CMC drop-in trigger. Insert into the lower receiver. The holes in the lower receiver should align with the holes on the trigger assembly.
11. Reinsert safety selector and tighten grip screw.
12. Install the CMC retaining pins, making sure that the holes are in alignment. Th pins should be flush with the lower receiver.
13. Apply a small amount of thread-locker to the first screw and insert into the pin. Snug down using the T10 Torx key. Don’t over-tighten the screws. Repeat for the remaining screws. Clean off any excess thread-locking compound.
14. Verify the installation by pulling the trigger with your thumb over the hammer, preventing it from dropping at full speed.
15. Reassemble the rifle. Perform an additional round of function checks.