USAS-12

The USAS-12 (Universal Sporting Automatic Shotgun, 12 gauge) is a selective-fire combat shotgun manufactured in South Korea by Daewoo Precision Industries. Its design descends from Maxwell Atchisson's automatic shotgun work of the 1980s: in about 1989 the Gilbert Equipment Company of the United States commissioned John Trevor Jr. to produce a select-fire weapon based on Atchisson's principles, but having no manufacturing capacity of its own, Gilbert had to find a builder. Daewoo was the only company willing to take it on, adapting the design to Korean production methods, and mass production began in the early 1990s.

The shotgun is gas operated and selective fire, intended to deliver sustained firepower at close quarters. The bolt locks on a single cylindrical locking piece that rises into a round recess in the barrel extension. It feeds from detachable 10-round box magazines or 20-round drums, both of polymer, with the rear of the drum made from translucent polymer so the remaining shell count can be read at a glance. Cyclic rate is 400 to 450 rounds per minute and effective range about 40 m. A CQ model introduced in the early 1990s drops the front sight and reshapes the carry handle.

More than 30,000 had been produced by the mid-1990s, selling well to military and security forces in Asia. Attempts to market a semi-automatic version in the United States failed when Treasury Secretary Lloyd Bentsen classified the weapon as having no sporting purpose, making it a destructive device under the National Firearms Act of 1934 and restricting civilian sales; RAMO Defence later assembled shotguns from Korean and American parts for government customers only. A semi-automatic clone called the WM-12, built by Ameetec Arms of Arizona from 2007, was discontinued after a pre-production run. The shotgun is still made in Korea by SNT Motiv for military and law enforcement sales.

Military and police users include the South Korean 707th Special Mission Group, Brazil's GRUMEC and army special forces battalions, Colombia's GAULA and COPES units, the Dominican Army, Peru and Thailand. It has also been documented in the hands of non-state groups including the Karen National Liberation Army, the New People's Army and Mexican cartel organisations.