Atchisson Assault Shotgun
||This article needs additional citations for verification. (August 2011)|
AA-12 Combat shotgun with magazine
|Place of origin||United States|
|Designer||Maxwell Atchisson, further developed by Military Police Systems, Inc.|
2005 MPS version
|Produced||soon to be confirmed|
|Weight||5.2 kg less magazine. 7.3 kg with loaded 32-round drum (original version)|
|Barrel length||457 mm|
|Rate of fire||300 rounds per minute|
|Muzzle velocity||350 m/s (1,100 ft/s)|
|Effective range||100 m (12 gauge slug)|
|Maximum range||200 m (FRAG-12 ammunition)|
|Feed system||8 rounds in box magazine, 20 or 32 rounds in drum magazines|
|Sights||Iron sight, 2x zoom optical scope|
The Auto Assault-12 (AA-12), originally designed and known as the Atchisson Assault Shotgun, is a shotgun developed in 1972 by Maxwell Atchisson. The current 2005 version has been developed over 18 years since the patent was sold to Military Police Systems, Inc. The original design was the basis of several later weapons, including the USAS-12 combat shotgun. The weapon is selective fire, operating as a semi-automatic, or in fully automatic mode at 300 rounds per minute. It is fed from either an 8-shell box magazine, or a 20- or 32-shell drum magazine.
In 1987, Max Atchisson sold the rights of AA-12 to Jerry Baber of Military Police Systems, Inc., Piney Flats, Tennessee. MPS in turn developed the successor simply known as Auto Assault-12, which was redesigned over a period of 18 years with 188 changes and improvements to the original blueprint, modifications included changing the AA-12 from blowback- to gas-operated with a locked breech. "When the bolt flies back after firing to cycle another round, around 80% of what would normally be felt as recoil is absorbed by a proprietary gas system. A recoil spring grabs another 10%, leaving the final recoil a remarkable 10% of the normal recoil for a 12-gauge round - so you can point the AA-12 at a target and unload the full magazine without significant loss of accuracy". MPS also teamed up with Action Manufacturing Company, and Special Cartridge Company to combine the gun with FRAG-12 High-Explosive ammunition into a multifunction weapon system.
The weapon was lightened to 4.76 kg (10.5 lb) and shortened to 966 mm (38.0 in) but retained the same barrel length. The CQB model has a 13-inch barrel, and is half a pound lighter than the regular model. Uncommon in other automatic shotguns, the AA-12 fires from an open bolt, a feature more commonly found in submachine guns and heavy and squad level machine guns. It uses 8-round box, 20-round drum, or 32-round drum magazines, as opposed to the original 5-round box magazine. Due to the abundant use of stainless steel and the designed clearance for fouling, MPS has claimed that the weapon requires little to no cleaning or lubrication. The designer states that cleaning is required after 10,000 rounds.
In 2004, ten firing models of the AA-12 were produced and demonstrated to the United States Marine Corps.
See also 
|AA-12 Fully Automatic Shotgun|
- Automatic shotgun
- Combat shotgun
- Daewoo USAS-12
- List of shotguns
- Military technology and equipment
- "Modern Firearms – Atchisson AA-12". Retrieved April 5, 2012.
- Moore, Jacob; Ruble, Drew (July/August 2009). "The Automatic Warrior". BusinessTN.
- http://www.gizmag.com/aa-12-combat-shotgun-frag-12-automatic/11393/. Missing or empty
- http://www.clcweb.net/Shooting/Military_Shotgun/military_shotgun.html[dead link] Military Assault Shotgun: "During a Blackwater shoot, 5000 rounds were fired through a single weapon without cleaning or a drop of Lube."
- Crane, David (June 15, 2005). "Auto Assault-12 (AA-12) Full-Auto Machine Shotgun/FRAG-12 High-Explosive Round Combo/Weapon System?".[self-published source?]
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- Blass, Evan (1 March 2006). "Neural Robotics Incorporated equips AutoCopter with 12-gauge shotgun". Retrieved 2 September 2011.
- "Remote Control Helicopter With Full-Auto Shotgun". 10 January 2008. Retrieved 2 September 2011.