The Daewoo USAS-12 is an automatic shotgun chambered in 12 gauge. It is produced by Daewoo Precision Industries, a South Korean manufacturer. The USAS-12 is based largely on the design principles of Maxwell Atchison’s 1980‘s automatic shotguns.
Based on these principles, the USAS-12 was designed by Gilbert Equipment Co. in the early 1990’s. The manufacturing was then contracted to Daewoo.
The USAS-12 employs a gas operating system and selective fire. In gas-operated systems, the pressurized gas released from the firing of an individual round is cycled through a tube and used to drive the bolt rearward to both eject the spent casing and the chamber a new round. The USAS-12 accepts 10-round box and 20-round drum detachable magazines. Newer magazines are made of polymer, and are translucent, allowing the user to visually check cartridge levels.
Although the USAS-12 is not available to civilians in North America, the gun has been sold widely to unspecified militaries in Asia.