[2] The USAS-12 is a gas-operated, selective fire weapon, designed to provide sustained firepower in close-combat scenarios.

In about 1989, Gilbert Equipment Co. (USA) decided to bring up the selective fired weapon, broadly based on principles employed in Atchisson shotguns.

Daewoo engineers adapted the new weapon to their manufacturing techniques, and mass production commenced in the early 1990s.

[3] The shotgun is still being manufactured by S&T Daewoo (now SNT Motiv) in Korea for military and law enforcement sales only.

[6] As of January 2008, however, the WM-12 was no longer to be found on Ameetec Arms online catalogs, because it was discontinued after its pre-production run.