Hello, I recently installed Bushmaster's two stage match trigger and after firing a few magazines, my rifle started doubling every third shot or so. I have cleaned the rifle before, but I have not taken the bolt apart and cleaned up the firing pin. I heard that a dirty firing pin could hang up and cause this problem. I also used Wheeler moly super lube on the new trigger if that makes any difference. I put about 2500 rounds through the gun with the stock trigger, and never had any problems. Thanks for any help, Gimpy.

You need to do a function test on the ”Unloaded” rifle/ fire control group.  

1. Lock the bolt back, hold the trigger back and hit the bolt release.  Did the hammer fall with the carrier slam, or can you  release the trigger and pull it again to get the hammer release?

2. Lock the bolt back, hit the release (don’t touch the trigger), did the hammer fall with the carrier slam or can you pull the trigger to get a hammer release after the slam?

3. Cock the rifle, while holding the trigger back, then very, very slowly release the trigger.  Did the primary sear catch the hammer, or did the disconnector sear release the hammer, miss the primary sear and the hammer struck the firing pin? A second pull on the trigger should release the hammer.

If the FCG passes all three of these tests (several times), then look at the firing pin/fouled bolt channel causing Slam firings. If it failed during one of above  tests, post back which one and we can help you solve the problem.

If you still have the instructions re-adjust the letoff and make sure the trigger spring is correctly installed. sounds like your 2nd stage is too light .