Bushmaster® Snake Charmer™II Muzzle Brake. This muzzle device has been redesigned to significantly reduce felt recoil. The Snake Charmer™II is the perfect addition to any Bushmaster® Firearm. – Caliber: 5.56 NATO / .223 REM – Thread Pitch: 1/2 x 28 – Finish: Salt Bath Nitride Proudly Made in U.S.A.