Assault Rifle

An assault rifle is a selective-fire rifle that uses an intermediate cartridge and a detachable magazine. Assault rifles were first used during World War II. Though Western nations were slow to accept the assault rifle concept after World War II, by the end of the 20th century they had become the standard weapon in most of the world's armies, replacing battle rifles and sub-machine guns. Examples include the StG 44, AK-47 and the M16 rifle.

Definition
In a strict definition, a firearm must have at least the following characteristics to be considered an assault rifle: The U.S. Army defines assault rifles as "short, compact, selective-fire weapons that fire a cartridge intermediate in power between submachine gun and rifle cartridges.
 * It must be an individual weapon
 * It must be capable of selective fire
 * It must have an intermediate-power cartridge: more power than a pistol but less than a standard rifle or battle rifle
 * Its ammunition must be supplied from a detachable box magazine
 * And it should have an effective range of at least 300 metres (330 yards)