I installed a Precision Armament M11 on a Bushy 308 ORC. The rifle was sighted in well with the POI about 2 inches above the POA at 100 yards. The rifle was in a vise when the A2 hider was removed there were flats on it to aid in removal. The M11 was threaded on it is snug not tight because I haven't ordered the proper shims. When I test fired it the POI had went down in a straight line exactly 5 inches. The scope or rifle wasn't bumped during my work and the scope adjusted up and stayed put, it's hard to imagine the brake changed the bullet flight that much but that's the way it seems.