The Steyr AUG (Armee-Universal-Gewehr—”universal army rifle”) is an Austrian 5.56×45mm NATO bullpup assault rifle, designed in the 1960s by Steyr-Daimler-Puch and now manufactured by Steyr Mannlicher GmbH & Co KG.
It was adopted by the Austrian Army as the StG 77 (Sturmgewehr 77) in 1978, where it replaced the 7.62×51mm NATO StG 58 automatic rifle (a licence-built FN FAL). In production since 1978, it is the standard small arm of the Austrian Bundesheer and various national police units. Its variants have also been adopted by the armed forces of dozens of countries.
Steyr AUG importation into the U.S. began in the 1980s as the AUG/SA (SA denoting semiautomatic). President George H.W. Bush banned the AUG via an executive order under the 1989 Assault Weapon Import ban. Six years into the ban, AUG buyers gained a reprieve as cosmetic changes to the carbine’s design allowed importation once again. Changes included the pistol grip being changed into a thumbhole stock, and the barrel left unthreaded to prevent attachment of flash suppressors and silencers. The ban sunsetted in 2004, and in 2008 Steyr Arms worked with Sabre Defense to produce parts legally in the U.S.
The Steyr AUG is a selective-fire, bullpup weapon with a conventional gas-piston-operated action that fires from a closed bolt. 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 AUG employs a very high level of advanced firearms technology and is made with the extensive use of polymers and aluminium components. It is chambered in 5.56×45mm NATO cartridge and has the standard 1:9 rifling twist that will stabilise both SS109/M855 and M193 rounds. Some nations including Australia, Ireland and New Zealand use a version with a 1:7 twist optimised for the SS109 NATO round. The submachine gun variants are chambered in 9×19mm Parabellum. The AUG consists of six interchangeable assemblies: the barrel, receiver with integrated telescopic sight or Picatinny rail, bolt carrier assembly, trigger mechanism, stock and magazine.
The AUG has a rotating bolt that features 7 radial locking lugs and is unlocked by means of a pin on the bolt body and a recessed camming guide machined into the bolt carrier. The bolt carrier itself is guided by two guide rods brazed to it and these rods run inside steel bearings in the receiver. The guide rods are hollow and contain the return springs. The bolt also contains a claw extractor that forms the eighth locking lug and a spring-loaded “bump”-type casing ejector.
The gas cylinder is offset to the right side of the barrel and works with one of the two guide rods. The AUG uses a short-stroke piston system where the right guide rod serves as the action rod, transmitting the rearward motion of the gas-driven piston to the bolt carrier. The left-hand rod provides retracting handle pressure when connected by the forward assist and can also be utilised as a reamer to remove fouling in the gas cylinder. The firearm uses a 3-position gas valve. The first setting, marked with a small dot, is used for normal operation. The second setting, illustrated with a large dot, indicates fouled conditions. The third, “GR” closed position is used to launch rifle grenades (of the non-bullet trap type).
The AUG is hammer-fired and the firing mechanism is contained in the rear of the stock, near the butt, covered by a synthetic rubber shoulder plate. The hammer group is made entirely of plastics except for the springs and pins and is contained in an open-topped plastic box which lies between the magazine and the buttplate. During firing the recoiling bolt group travels over the top of it, resetting the hammer. Since the trigger is located some distance away, it transmits its energy through a sear lever which passes by the side of the magazine. The firing pin is operated by a plastic hammer under pressure from a coil spring.
The AUG comes standard with four magazines, a muzzle cap, spare bolt for left-handed shooters, blank-firing adaptor, cleaning kit, sling and either an American M7 or German KCB-77 M1 bayonet.
Muzzle devices and barrel lengths
A three-pronged, open-type flash suppressors were used on the 350 mm (13.8 in), 407 mm (16.0 in) and 508 mm (20.0 in) length barrels, whereas the 621 mm (24.4 in) light machine gun barrel received a closed-type ported muzzle device (combination flash suppressor and compensator) and an integral, lightweight folding bipod. The flash suppressors are screwed to the muzzle and internally threaded to take a blank-firing attachment.
The AUG features an Spz-kr type progressive trigger (pulling the trigger halfway produces semi-automatic fire, pulling the trigger all the way to the rear produces fully automatic fire) and a safety mechanism (cross-bolt, button type), located immediately above the hand grip. In its “safe” position (white dot) the trigger is mechanically disabled; pressing the safety button to the left exposes a red dot and indicates the weapon is ready to fire. Some versions have an ALO or “automatic lockout”, a small projection at the base of the trigger. This was first included on the Irish Defence Forces variant of the rifle, and soon after, the Australian Defence Forces variant. In the exposed position the ALO stops the trigger being squeezed past the semi-automatic position. If needed, the ALO can be pushed up to permit automatic fire.
The AUG is fed from a translucent, double-column box magazines (molded from a high-strength polymer) with a 30-round capacity and an empty weight of 130 g (4.6 oz). The light machine gun variant of the AUG uses an extended 42-round magazine. An Argentine variant of the FN FAL chambered in 5.56×45mm NATO cartridge and known as the FALMP III Type 2 also uses the same magazine.
The AUG has a 1.5× telescopic sight that is integrated with the receiver casting and is made by Swarovski Optik. It contains a simple black ring reticle (“donut of death”) with a basic rangefinder that is designed so that at 300 m (984.3 ft) a 180 cm (5 ft 11in) tall man-size target will completely fill it, giving the shooter an accurate method of estimating range. The sight cannot be set to a specific range but can be adjusted for windage and elevation for an initial zero and is designed to be calibrated for 300 m. So when it is set, aiming at the centre of a target will produce a hit at all ranges out to 300 m. It also has a backup iron sight with a rear notch and front blade, cast into the top of the aluminium optical sight housing, used in case of failure or damage to the primary optical sight. The sight is also equipped with a set of three illuminated dots (one on the front blade and two at the rear) for use in low-level lighting conditions. In order to mount a wide range of optics and accessories, a receiver with a NATO-standard Picatinny rail and detachable carrying handle was also developed and introduced in December 1997.
The Steyr AUG is a bullpup assault rifle chambered in 5.56×45mm NATO. It was introduced in 1978 and was adopted by the Austrian Army and was designated as the StG 77 in 1978, then it was later adopted by several military agencies around the world.
- The Steyr AUG A1 is an improved variant of the AUG and was introduced in 1982. It is available with a choice of olive or black furniture. The Australian Army adopted the Steyr AUG A1 and designated it as the F88 Austeyr. It has a cyclic rate of fire of around 680–850 rounds per minute.
- The Steyr AUG M203 is an AUG A1 fitted with the M203 grenade launcher.
- The Steyr AUG AG-C is an AUG A1 fitted with the AG-C grenade launcher.
- The Steyr AUG A2 features a redesigned charging handle and a detachable telescopic sight which can be replaced with a MIL-STD-1913 rail. Due to its modularity, a 24-inch barrel can be used and a Picatinny rail section can be fitted instead of the folding grip, where a bipod can be installed. The rifle was introduced in December 1997.
- The Steyr AUG A3 features a MIL-STD-1913 rail on top of the receiver and an external bolt release.
- The Steyr AUG A3 SF also known as the AUG A2 Commando, features an MIL-STD-1913 rails mounted on the telescopic sight and on the right side of the receiver, and includes an external bolt release. The integrated telescopic sight is offered in 1.5× or 3× magnification.
- The Steyr AUG A3-CQC was a prototype development of the AUG A3 and was first displayed by Steyr at the SHOT Show 2006. It differs in having a railed handguard attached ahead of the receiver. Due to the need to remove this extra railed section in order to strip the rifle for cleaning, it featured a quick detach lever mounted on the left side to remove the rail. Due to the concerns over the extra cost and weight, along with potential issues with the reliability and consistency of the detachable handguard, the prototypes received little interest and were last seen promoted by Steyr in 2008 and likely has been cancelled. In total only 5 prototypes were made, four with standard 18-inch barrels, and one with a longer heavy marksman barrel and a 20-round magazine. In 2012 the American company PJA obtained the 5 original prototypes from Steyr and reverse engineered them in order to produce a US-made AUG A3-CQC and conversion kits.
The Steyr AUG HBAR (Heavy Barreled Automatic Rifle) is a longer heavier-barreled variant of the standard AUG for use as a light machine gun or squad automatic weapon. Its telescoping sight has a 4× magnification rather than the 1.5× magnification of the standard AUG. It can be modified to fire from an open bolt to allow sustained fire. To accomplish this, a modified bolt carrier, striker and trigger mechanism with sear are used.
- The Steyr AUG HBAR-T (Heavy Barreled Automatic Rifle-Telescope) is a designated marksman configuration of the HBAR that features a special receiver fitted with a Kahles ZF69 6×42 optical sight.
The Steyr AUG Para also known as the AUG SMG or AUG 9mm, is a submachine gun variant of the AUG chambered in 9×19mm Parabellum cartridge and has been produced since 1988. It differs from the rifle variants by having a different barrel, bolt and magazine. It is an automatic, blowback-operated model that fires from a closed bolt, and does not use of the rifle’s gas system. Unlike the rifle variants, it has a unique 420 mm (16.5 in) barrel with six right-hand grooves at a 250 mm (1:9.8 in) rifling twist rate, with a recoil compensator, a slightly different charging handle and a magazine well adapter enabling the use of standard 25-round box magazines from the Steyr MPi 69 and TMP submachine guns. A conversion kit used to transform any assault rifle configuration into the submachine gun configuration is also available. The conversion kit consists of a barrel, bolt, adapter insert and magazine.
- The Steyr AUG A3 Para XS is a 9mm variant of the AUG A3. It features a 325 mm (12.8 in) barrel and a Picatinny rail system.
- The Steyr AUG 40 is a .40 S&W variant of the AUG Para that uses Glock compatible double stack .40 S&W magazines.
|Action||Gas-operated, rotating bolt|
|Rate of fire||680–750 rounds/min|
|Muzzle velocity||Standard rifle: 970 m/s (3,182 ft/s)|
|Effective firing range||300 metres (980 ft)|
|Maximum firing range||2,700 metres (8,900 ft)|
|Sights||Swarovski 1.5× telescopic sight, emergency battle sights, and Picatinny rail for various optics|