TROY Industries Claymore Muzzle Brake, Not Compatible with any M-14/M1A rifles, 7.62 NATO/.308/6.8, (5/8 X24 TPI), Black SBRA-CLM-06BT-00 The Troy Claymore Muzzle Brake(TM) directs muzzle blast and sound forward" away from the shooter" while retaining effective muzzle brake properties. This rugged muzzle brake features a very low dust signature without a swirling effect and is tough enough to serve as an improvised breaching device if the situation calls for it.