STG-556

STG-556
TypeAssault rifle/Semi-automatic rifle
Place of originUnited States
Production history
DesignerSteyr Arms
ManufacturerMicrotech Small Arms Research
Produced2007-15
No. built
  • 1000 (Limited edition STG-556)
  • 232 (STG-556 rifles with an 18.5" heavy barrel)
  • 500 (STG-556 Gebirgsjäger)
VariantsSee Variants
Specifications
Mass
  • Empty: 3.62 kg (8.0 lb)
Length
  • 26 in (660.4 mm)
  • 27 in (685.8 mm)
  • 31 in (787.4 mm)
Barrel length
  • 14 in (355.6 mm)
  • 16 in (406.4 mm)
  • 18.5 in (469.9 mm) (only for .300 Blackout)
  • 20 in (508.0 mm)
Cartridge
ActionGas-operated, rotating bolt, short piston drive
Feed system
  • 10/20/30/42-round detachable box magazine
  • 30-round magazine (7.62/5.45 variants)
  • STANAG magazine (XM17-E4 only)
Sights
  • 1.5x optical sight
  • Can have various scopes/sights installed via picatinny railing
References[1][2][3][4]

The STG-556 is a Steyr AUG clone formerly manufactured by Microtech Small Arms Research (MSAR).[5] It was available in civilian and military/law enforcement (select-fire) variants.[6]

History

It was introduced at the 2007 SHOT Show. The first few STG-556 rifles were chambered in .223 Caliber.[4]

In July 2012, MSAR resurfaced with a new STG-556 rifle variant known as the STG-E4.[7]

MSAR closed down permanently on March 20, 2015.[8] No specific reasons were stated on their website, but it is well known that Steyr setting up a US based manufacturing arm, producing genuine Steyr AUG firearms, all but eliminated the need for anyone to buy a clone.[5]

Design

The STG-556's design was based on the original Steyr AUG since the patents expired at the time.[6] The frame was made on 7075 T6 aircraft-grade aluminum[9] and made from cast, unlike the TPD AXR as it was made through forging.[10] It was available in black, tan and green finish.[9]

It features a bolt release as seen on the M16 rifle[6] and a forward assist.[9] Otherwise, the STG-556 retains the features similar to the Steyr AUG, such as having the quick-change barrel option and the ability to change which side the weapon ejects from by changing the bolt out for a right or left side bolt respectively. The STG-556 has a right-side ejector.

When using a suppressor or low-pressure ammo, the gas regulator needs to be adjusted to allow more gas to be used to fire ammo.[11] The gas regulator positions consist of "S", which is the normal setting and allows large amounts of gas to escape from the rifle.[12] "H" diverts more gas into the rifle to allow the STG-556 to be fired in adverse conditions or extreme foulings.[12] "GR" diverts gas into the system to fire blanks in order to launch rifle grenades.[12]

The STG-556 uses a short-stroke gas piston. The rifle can be converted from either having a telescopic sight or a MIL-STD-1913 rail.[6] Various accessories can be attached on the rail.[13]

The STG-556 uses magazines similar to those used by the Steyr AUG (10/20/30/42),[14] being made up of “radel” (polyphenylsulfone).[11] The rifles can also take 30-round STANAG and Magpul PMAG magazines.[10] The XM-17E4 variant can use STANAG magazines.

Most STG-556 rifles made in 2009 did not allow to use AUG-type magazines unless the three ribs on top were professionally filed off.[12] All STG-556s without a forward-assist mechanism can take AUG magazines.[12]

The barrel can accept a blank adapter or a suppressor.[15]

Variants

STG-556 Limited Edition

A limited edition STG-556, a clone of the Steyr AUG A3, had a production run of only 1,000 rifles. There was a limited production of 232 rifles produced with an 18.5" heavy barrel after tests proved that length provided optimum accuracy over the 24" length due to barrel harmonics.

STG-556 Gebirgsjäger

The STG-556 Gebirgsjäger had a production run of 500 rifles. It was named after the Gebirgsjäger, which means Mountain Huntsmen.[16] It was previously sold with an OD green Currahee Knife and a MSAR Pelican 1700 case.[16]

STG-556 E4

The STG-556 E4 was introduced in 2009.[12] It can use AR-15 and M16 magazines.[4] For any E4s that use .300 AAC Blackout, they can use the 18.5" barrel.[17]

References

  1. ^ "Microtech Small Arms Research - STG-556 Sporting Rifle". www.msarinc.com. Archived from the original on 10 February 2010. Retrieved 30 June 2022.
  2. ^ "Archived copy" (PDF). www.msarinc.com. Archived from the original (PDF) on 9 December 2008. Retrieved 30 June 2022.{{cite web}}: CS1 maint: archived copy as title (link)
  3. ^ "Msar | STG-556". msarinc.com. Archived from the original on 6 February 2011. Retrieved 30 June 2022.
  4. ^ a b c Choat, Chris (March 2008). "Microtech's STG-556 An Exclusive First Look". The Small Arms Review. 11 (6): 43–50.
  5. ^ a b "MSAR STG-556: Bullpup You'll Recognize". Archived from the original on 2023-05-09.
  6. ^ a b c d "MSAR STG-556 rifle". 27 October 2010.
  7. ^ "Microtech Small Arms Research (MSAR) STG-E4 Rifle". 23 July 2012.
  8. ^ "Microtech Small Arms Research Closes Its Doors -". 23 March 2015.
  9. ^ a b c "Microtech STG-556". 23 September 2010.
  10. ^ a b "MSAR STG-556 Bullpup Rifle (4179 STANAG) and Translucent Polymer AR Magazine".
  11. ^ a b "MSAR STG-556 Gebirgsjäger". 14 September 2009.
  12. ^ a b c d e f "STG-556: American Combat Bullpup: If you missed the chance to buy an AUG back in the '80s, here's your chance to buy a U.S.-made version with some interesting improvements. - Free Online Library".
  13. ^ "Msar STG-556". May 2008.
  14. ^ "MSAR Magazines – Civilian Tactical Weapons".
  15. ^ "MICROTEch's STG-556 AN EXCLUSIVE FIRST LOOK - Small Arms Review". 5 March 2008.
  16. ^ a b "Microtech Small Arms Research - Home". msarinc.com. Archived from the original on 10 February 2009. Retrieved 30 June 2022.
  17. ^ "MSAR Returns with New STG-E4 AUG-Style Rifles".