Muzzle Brake - Concept

Concept

Muzzle brakes are simple in concept. One of the simplest designs can be found on U.S. 90 mm tank guns as used on the M47 Patton tank. This consists of a small length of tubing mounted at right angles to the end of the barrel. Brakes most often utilize slots, vents, holes, baffles, and similar devices. The strategy of a muzzle brake is to redirect and control the burst of combustion gases that follows the departure of a projectile.

All muzzle brake designs share a basic principle: combustion gases are diverted at a sideward or sideward and rearward angle (or direction) away from the muzzle end of the bore line. The resulting change in the gases' momentum creates a reaction force which helps to counteract the rearward movement of the barrel (due to recoil) as well as the upward rise of the muzzle. The effect can be compared to reverse thrust systems on aircraft jet engines. The mass and velocity of the gases is significant enough to move the firearm in the opposite direction of recoil. On the AKM assault rifle, the brake is angled slightly to the right to counteract the sideways movement of the gun under recoil.

Another method of redirecting gases is called porting. Porting involves creating ports or holes that are precision-drilled into the forward part of the barrel (and slide on pistols and shotguns). These holes are designed to divert a portion of the gases expelled prior to the departure of the bullet in the direction that reduces the tendency of the firearm to flip upwards. The concept applies Newton's third law: the exhaust directed upward causes a reciprocal force downward. Porting is most commonly used on shotguns, where recoil is most significant and makes rapid firing difficult. Even single shots of magnum-strength loads are uncomfortable for all but the most seasoned shooters. Porting has obvious advantages for faster follow-up shots, especially for 3-round burst operation.

Another strategy (besides redirecting gases) for counteracting muzzle rise involves slowing the departure of combustion gases. Slowing of the gases is the method used on suppressors and linear compensators.