It is designed as a Modular Weapon System that could be quickly configured as a rifle, a carbine, a sniper rifle, a sub-machine gun and even an open-bolt squad automatic weapon.

The Steyr AUG is a selective-fire, bullpup weapon with a conventional gas-piston-operated action that fires from a closed bolt. 1.2.1 Muzzle devices and barrel lengths.

The ban sunsetted in 2004, and in 2008 Steyr Arms worked with Sabre Defense to produce parts legally in the U.S. Changes included the pistol grip being changed into a thumbhole stock, and the gun barrel left unthreaded to prevent attachment of flash hiders and suppressors. Six years into the ban, AUG buyers gained a reprieve as cosmetic changes to the carbine's design allowed importation once again. Bush banned the AUG via an executive order under the 1989 Assault Weapon Import Ban. Steyr AUG importation into the United States began in the 1980s as the AUG/SA (SA denoting semiautomatic). In production since 1978, it is the standard small arm of the Bundesheer and various Austrian federal police units, and its variants have also been adopted by the armed forces of dozens of countries, with some using it as a standard-issue service rifle. It was adopted by the Austrian Army in 1978 as the StG 77 ( Sturmgewehr 77), where it replaced the 7.62Г—51mm NATO StG 58 automatic rifle (a licence-built FN FAL). The Steyr AUG ( German: Armee-Universal-Gewehr, lit.'universal army rifle') is an Austrian bullpup assault rifle chambered for the 5.56Г—45mm NATO intermediate cartridge, designed in the 1960s by Steyr-Daimler-Puch, and now manufactured by Steyr Arms GmbH & Co KG. Swarovski 1.5Г— telescopic sight, emergency battle sights, and Picatinny rail for various optics 9Г—19mm Parabellum: 25-, 32-round detachable MPi 69 box magazine.5.56Г—45mm NATO: 30-, 42-round detachable box magazine, or STANAG magazine.

Steyr mannlicher holding gmbh