The AA-12 (Auto Assault - 12), originally designed and known as the Atchisson Assault Shotgun, is a
fully automatic combat shotgun developed in 1972 by Maxwell Atchisson. However, the original development by Atchisson seems to have produced only a few guns at prototype-level, with the development that ultimately led to the gun entering the market being done later by Military Police Systems, Inc. The most prominent feature is reduced recoil. The 2005 version was developed 19 years after the patent was sold to Military Police Systems, Inc. The original design later led to the development of several comparable firearms of such utility, including the
USAS-12 combat shotgun. The shotgun utilizes
fully automatic blowback action as its primary and only mode of fire. However, the relatively low cyclic rate of fire of around 300 rounds per minute enables the shooter to fire individual rounds through the use of short trigger pulls. It is fed from either an 8-round
box magazine
A magazine, often simply called a mag, is an ammunition storage and feeding device for a repeating firearm, either integral within the gun (internal/fixed magazine) or externally attached (detachable magazine). The magazine functions by holdi ...
or 20-round
drum magazine
A drum magazine is a type of high-capacity magazine for firearms. Cylindrical in shape (similar to a drum), drum magazines store rounds in a spiral around the center of the magazine, facing the direction of the barrel. Drum magazines are contra ...
. The
charging handle is located at the top of the gun and does not reciprocate during firing.
History
In 1987, Max Atchisson sold the rights of the 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 with the help of
German-born machinist Boje Cornils, who redesigned the weapon over a period of 19 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. Upon firing a 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 felt recoil only 10% of the normal 12-gauge round. MPS also teamed up with Action Manufacturing Company and Special Cartridge Company to combine the gun with
FRAG-12 High-Explosive ammunition as a multifunction weapon system.
The weapon was lightened to and shortened to but retained the same barrel length. The
CQB model has a 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 firearm is said to fire from an open bolt or open breech if, when ready to fire, the bolt and working parts are held to the rear of the receiver, with no round in the chamber. When the trigger is actuated, the bolt travels forward, feeds a car ...
, a feature more commonly found in submachine guns, as well as heavy and squad-level machine guns. The weapon uses an Advanced Primer Ignition blowback which strikes the shotgun shell when moving forward before placed in-battery (fully chambered), overcoming the forward inertia of the bolt and offering low recoil. It uses 8-round box or 20-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 stated that the weapon requires little to no cleaning or lubrication. The designer states that cleaning is required after 10,000 rounds. A rail system is also available for modern sighting options. Because of an open bolt design, the AA-12 can reportedly operate after being submerged in water.
In 2018, the company Sol Invictus arms introduced a
Semi-automatic version of the AA-12 for the civilian market, being featured in the
SHOT Show
The SHOT Show, which is an acronym for "Shooting, Hunting, and Outdoor Trade Show", is an American annual trade fair, trade show for the shooting sports, hunting, outdoor recreation, and firearm manufacturing industry (economics), industries. The ...
2019. In late 2019, the
Bureau of Alcohol, Tobacco, Firearms and Explosives
The Bureau of Alcohol, Tobacco, Firearms and Explosives (BATFE), commonly referred to as ATF, is a domestic law enforcement agency within the United States Department of Justice. Its responsibilities include the investigation and prevention ...
ordered a recall of civilian AA-12 shotguns produced by BC Engineering (a company owned by Boje Cornils), claiming that the semi-automatic shotgun was a machine gun. As a result Sol Invictus Arms paused the production of their AA-12.
Ammunition
The AA-12 is capable of firing various types of 12-gauge ammunition such as
buckshot
A shotgun cartridge, shotshell, or shell is a type of rimmed, cylindrical (straight-walled) ammunition used specifically in shotguns. It is typically loaded with numerous small, spherical sub-projectiles called shot. Shotguns typically use a ...
and
slugs
Slug, or land slug, is a common name for any apparently shell-less terrestrial gastropod mollusc. The word ''slug'' is also often used as part of the common name of any gastropod mollusc that has no shell, a very reduced shell, or only a sma ...
.
Usage
By 2004, ten firing models of the AA-12 had been produced and were demonstrated to the
United States Marine Corps
The United States Marine Corps (USMC), also referred to as the United States Marines or simply the Marines, is the maritime land force service branch of the United States Department of Defense. It is responsible for conducting expeditionar ...
, who did not adopt the weapon.
The Hammer unmanned defense system by More Industries proposed to use dual-mounted AA-12s on the H2X-40 turret. Neural Robotics also wanted to mount the weapon on their AutoCopter
unmanned aerial vehicle
An unmanned aerial vehicle (UAV) or unmanned aircraft system (UAS), commonly known as a drone, is an aircraft with no human pilot, crew, or passengers onboard, but rather is controlled remotely or is autonomous.De Gruyter Handbook of Dron ...
.
See also
*
Armsel Striker
*
List of API blowback firearms
*
List of shotguns
Shotguns have traditionally fired iron, Rock (geology), stone or lead shot stored in large shells that are normally loaded.
See also
*Semi-automatic shotgun, Assault shotgun
*Automatic shotgun
*Combat shotgun
*List of bullpup firearms
*List ...
*
Pancor Jackhammer
*
Saiga-12
References
{{API blowback firearms
Weapons and ammunition introduced in 1972
API blowback firearms
Automatic shotguns
Shotguns of the United States