We have post ban muzzle brakes that slipover the muzzle that we pin in place with a front sight base taper pin using a high strength sleeve and bearing Loctite.
We have the Izzy, AK and Mini-Y-Comp muzzle brakes available. The Izzy muzzle brake is the most popular.
Muzzle brakes work by redirecting muzzle gases which increases noise to the shooter.
If you send us your barreled upper assembly we will install a post ban muzzle brake at no additional charge. It is the cost of the muzzle brake and return shipping. Bushmaster will only warranty factory installation of post ban muzzle brakes.