The MB556K-SB muzzle brake fits the Colt Commando, M4, M16, HK 416, and other 5.56mm (.223 cal.) semi-auto, bolt-action, or assault rifles with Mil-Spec 1/2-28 muzzle threads, and is specially designed for short-barreled rifles so that the locking ring of a SureFire Fast-Attach®suppressor will clear the weapon's accessory rail.
The MB556K-SB muzzle brake greatly reduces both recoil and up-and-right muzzle movement to keep you on target for faster follow-up shots, while the patented Impulse Diffusion design minimizes side blast and rear-directed concussion effects. Machined from heat-treated stainless steel and finished in a tough, corrosion-resistant coating, all SureFire muzzle brakes are extremely resistant to gas and particle erosion and will perform perfectly for thousands of rounds.
The MB556K-SB muzzle brake also serves as a precision, rock-solid adapter mount that enables rapid no-tools attachment of SureFire FA556K, FA556-212, FA556MG, MINI, or MICRO suppressors to the Colt Commando, M4, M16, HK 416 with 14.5" or longer barrel, and to other 5.56mm (.223 cal.) semi-auto, bolt-action, or assault rifles with Mil-Spec 1/2-28 muzzle threads and (due to slight suppressor overlap) first .170" of barrel behind the threads clear of obstructions and no more than .800" in diameter. Link to parts manufacturer