Atchisson AA-12

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 or 20-round drum magazine. The charging handle is located at the top of the gun and does not reciprocate during firing.