Steyr AUG is an assault rifle designed and built in Austria and came into service in 1977. Today it is a standard light assault rifle in countries all around the globe including United States. Steyr AUG was tested in many combat situations including in the Afghanistan and Iraq war. Many versions of AUG were built but all use 5.56mm NATo ammunition with conventional gas piston operated action. The basic AUG rifle uses a 30-round magazine box. To increase weapons accuracy, it uses an integrated 1.5x telescopic sight. With it, AUG is effective in all ranges from 300-500m away. Three open-type flash suppressors were also used. Many variations and barrel lengths were made for different purpuses. From 350mm barrel to 621mm barrel. Some were even equipped with small grenade launchers and there is a place for bayonet.
Many variants were created to meet the demands for different purposes:
* AUG A1 – standard version from 1977
* AUG A2 – an upgrade from A1, it features a redesigned charging handle and a detachable telescopic sight
* AUG A3 – another upgrade from A1 and A2, but features a MIL-STD-1913 rail on top of the receiver, and an external bolt release
* AUG A3 SF – Similar to the AUG A2, but features MIL-STD-1913 rails mounted on the telescopic sight and on the right side of the receiver, and includes an external bolt release
* AUG A3 SA USA – Semi-automatic AUG A3 with a 407 mm (16.0 in) barrel
* AUG P – Semi-automatic AUG A1 with a shorter, 407 mm (16.0 in) barrel.
* AUG P Special Receiver – Similar to the AUG P, but features a MIL-STD-1913 rail on top of the receiver.
* AUG 9mm – Chambered in 9x19mm Parabellum and produced since 1988.
* AUG A3 9mm XS – 9mm version of the AUG A3, similar to the AUG 9mm. Features a 325 mm (12.8 in) barrel and Picatinny rail system.
* AUG M203 – An AUG modified for use with the M203 grenade launcher.
* AUG LSW – A family of light support versions of the AUG.
* AUG HBAR – A longer, heavier-barreled version for use as a light machine gun.
* AUG LMG – Based on the AUG HBAR, fires from an open bolt, has 4x rather than 1.5x optic of the base AUG.
* AUG LMG–T – Same as LMG, but has rail similar to the AUG P Special Receiver.
* AUG HBAR–T – A designated marksman rifle based on the HBAR with a universal scope mount cast into the receiver and fitted with a Kahles ZF69 6×42 optical sight.
* AUG Z – Semi-automatic version, somewhat similar to the A2, intended primarily for civilian use.
* AUG SA – Semi-automatic version of the A1 variant; built for civilian use and import to the US before being banned from importation in 1989.
* USR – An AUG A2 modified to meet U.S. BATF regulations, with modifications including a thumbhole grip.