AutocannonAn autocannon, automatic cannon or machine cannon is a fully automatic gun that is capable of rapid-firing large-caliber ( or more) armour-piercing, explosive or incendiary shells, as opposed to the smaller-caliber kinetic projectiles (bullets) fired by a machine gun. Autocannons have a longer effective range and greater terminal performance than machine guns, due to the use of larger/heavier munitions (most often in the range of , but bigger calibers also exist), but are usually smaller than tank guns, howitzers, field guns, or other artillery.
RecoilRecoil (often called knockback, kickback or simply kick) is the rearward thrust generated when a gun is being discharged. In technical terms, the recoil is a result of conservation of momentum, as according to Newton's third law the force required to accelerate something will evoke an equal but opposite reactional force, which means the forward momentum gained by the projectile and exhaust gases (ejectae) will be mathematically balanced out by an equal and opposite momentum exerted back upon the gun.
Assault rifleAn assault rifle is a selective fire rifle that uses an intermediate cartridge and a detachable magazine. Assault rifles were first put into mass production and accepted into widespread service during World War II. The first assault rifle to see major usage was the German StG 44, a development of the earlier Mkb 42. While immediately after World War II, NATO countries were equipped with battle rifles, the development of the M16 rifle during the Vietnam War prompted the adoption of assault rifles by the rest of NATO.
Light machine gunA light machine gun (LMG) is a light-weight machine gun designed to be operated by a single infantryman, with or without an assistant, as an infantry support weapon. LMGs firing cartridges of the same caliber as the other riflemen of the same combat unit are often referred to as squad automatic weapons. While early light machine guns fired full-powered rifle cartridges, modern light machine guns often fire smaller-caliber rifle cartridges than medium machine guns – generally the same intermediate cartridge fired by a service's standard assault rifle – and are usually lighter and more compact.