Definition

The term assault rifle is a translation of the German word Sturmgewehr (literally meaning "storm rifle"), "storm" used as a verb being synonymous with assault, as in "to storm the compound".

Sturmgewehr was coined by Adolf Hitler[1] to describe the Maschinenpistole 44, subsequently re-christened Sturmgewehr 44, the firearm generally considered the first true assault rifle that served to popularize the concept.

The translation assault rifle gradually became the common term for similar firearms sharing the same technical definition as the StG 44. In a strict definition, a firearm must have at least the following characteristics to be considered an assault rifle:

• It must be an individual weapon with provision to fire from the shoulder;
• It must be capable of selective fire;
• It must have an intermediate-power cartridge between pistol and traditional rifle;
• Its ammunition must be supplied from a detachable box magazine.

The term "assault rifle" is often more loosely to include other types of arms, particularly arms that fall under a strict definition of the battle rifle, or semi-automatic variant of military rifles for commercial or political reasons.

The US Army defines assault rifles as "short, compact, selective-fire weapons that fire a cartridge intermediate in power between submachinegun and rifle cartridges".

http://en.wikipedia.org/wiki/Assault_rifle