The Steyr AUG is an Austrian assault rifle introduced in 1977. In Austrian service it is designated StG-77 (for Sturmgewehr 77, German for Assault Rifle 77). AUG stands for Armee Universal Gewehr, meaning Army Universal Rifle. Design - The AUG is one of the first rifles to enter service designed on a Bullpup principle; this makes it 25% shorter than other rifles with similar barrel lengths, without compromising ballistic performance. It comes factory-equipped with a low magnification optical sight/carrying handle. The AUG is generally regarded as a modern ergonomic design for a combat rifle. Barrels of the Steyr AUG can be changed quickly and easily, changing the rifle from a carbine (short rifle) to an assault rifle (medium barrel) to a light machine gun or heavy sniper barrel.