Muzzle Brake

Ultradyne Mercury/C4 Dynamount Sight Combo U.S.A. –-( was contacted by Ultradyne to see if I would be interested in testing out a couple of their products. They make some very high-end AR-15 parts, and I needed an excuse to build another AR-15, so I said: “why not?” Ultradyne sent me their Mercury/C4 Dynamount Sight Combo.