 The muzzle booster is distinct from the muzzle brake, which is designed to use the propellant gases to reduce the recoil of the firearm.However, unlike a muzzle brake, a muzzle booster uses the pressure of the expanding gases, rather than the reaction force, and it does not alter the felt recoil of the weapon, it merely adds more energy to the operating components.The recoil booster was first introduced in the Vickers machine gun of 1912.