A muzzle brake or compensator is a device that is fitted to the muzzle of a firearm or cannon to redirect propellant gases with the effect of countering both recoil of the gun and unwanted rising of the barrel during rapid fire. Muzzle brakes are very useful for combat and timed competition shooting, and are commonly found on rifles firing very large cartridges (often big-game rifles), as well as some artillery and tank guns. They are also commonly used on pistols for practical pistol competitions, and are usually called compensators in this context. On the AKM assault rifle, the brake is angled slightly to the right to counteract the sideways movement of the gun under recoil.
Muzzle brakes often take the form of a short extension of the gun's barrel, and they are often slightly, if not significantly, larger in diameter than the barrel. For these reasons, many people, especially those not very familiar with firearms, mistake muzzle brakes for so-called silencers (suppressors.) The two devices are actually entirely different and serve totally different purposes