TROY Industries Medieval Muzzle Brake, 556NATO, 1/2X28HR, Fits AR Rifles, Black Finish SBRA-MED-05BT-00 Keep steady during rapid fire with our Medieval(TM) Muzzle Brake. This rugged brake enhances control and accuracy during full auto and rapid fire. The aggressive diamond-shaped teeth are designed for close quarter battle. It's tough enough to serve as an improvised breaching device if the situation calls for it.