Daewoo USAS-12

The Daewoo USAS-12 is a fully-automatic shotgun and uses standard 12-gauge shells (00-buckshot, loaded into either 10 round magazines or 20 round drums). The design is based on the Atchison Assault shotgun - few also believe that it is based on M16 long recoil system.

In 1989, Gilbert Equipment Co., (USA) decided to manufacture selective firearms based on Atchison shotguns. John Trevor Jr. designed this weapon. Since Gilbert Equipment Co., did not have manufacturing base, it explored partners. The South Korean Daewoo Precision Industries, a part of the high-tech Daewoo conglomerate, agreed to manufacture this weapon. In early 1990s, Daewoo engineers adopted the new shotgun to their manufacturing techniques, and the production was started. The gun made brisk business in military and security forces in Asia, and more than 30,000 of USAS-12 were made by mid-1990s. The original Daewoo/Atchison shotgun was AA-12 assault shotgun, a product to fire standard and exotic ammunition. The AA-12 was modified by Daewoo in hopes of increasing the U.S. sales and renamed as it USAS-12.

However, due to its categorization as Class III destructive devices in the US, it is restricted in civilian use. It is still manufactured in South Korea, and in the U.S. RAMO Defense Co. assembles USAS-12 and sells to government/military agencies. The US army on trial basis is using this weapon in Iraq and Afghanistan for close combat situations. It is well-liked by the troops for incredible firepower; however, it is very bulky and heavy and is designed for the physically strong users. Its large weight greatly helps the recoil control.

It has venerable 12-gauge round that is fired both on automatic or semi-automatic modes. It is flexible in magazines, feeds both 7 and 10 round box magazines or a special 20 round drum for sustained firing. The two types of magazines are made of polymer, and drum magazines rear side is made of translucent polymer for quick view of left shots. It is seen as accurate and controllable, and is designed for CQC (close quarters combat) and door-breaching as most combat shotguns. Rapid bursts of 12-guage slugs usually reduce barriers to splinters. With its 650 rounds per minute fire rate, it can havoc a place, which was not considered during the design process.

Above the barrel, a gas system is mounted similar to rotating bolt locking. One unique feature is that it has long bolt overt ravel, borrowed from Atchison designs. This allows in relatively low peak recoil and low rate of fire, an essential aspect for a powerful 12-gauge shells. It is an ambidextrous shotgun, with two ejection ports on each side of the receiver, and two slots on the forearm for cocking handle. Depending on the operator preferences, the ejector on the bolt and the cocking handle can be operated either side of the gun.