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.
[2] 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. 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