Thread: AR15 Issue?

Dirty Brass is normal with a can.

Check:

Groups without suppressor
Barrel nut is tight (can you move the barrel back and forth with your hand whilst holding the handguard)
Scope tracks correctly (when you adjust 1" does it move 1")
Scope mounts are tight
Barrel twist is fast enough for projectile weight (1:12 up to 60 grains, 1:9 up to 69 grains, 1:8 up to 75 grains, 1:7 up to 90 grains)
Gas Key (the thing on top of the bolt) is staked and not moving
Gas tube / Gas block is all tight

Let us know after that...