This is a exceptional example of an experimental "K-1200" High Standard trench shotgun developed for the USAF in the early 1970s. High Standard developed these based on the continuing use and need for a trench shotguns in Vietnam. It is estimated 25-50 were actually manufactured and test samples were sent to the USAF, Navy and Army. With the Vietnam War slowing to come to a close starting in late 1972, the military did not proceed any further with the development of this model. Later, the Army went to a combined riot/trench shotgun configuration with a performance specification and eventually awarded future contracts to the Mossberg Company starting in the early 1980s. The left side of the barrel under the heat shield/handguard is marked "RIOT 1200-------MODEL K-1200 HIGH STANDARD COMPANY/HAMDEN CONN. U.S.A." with the top and breech end of the barrel stamped are with the date code of "CL". The left rear end of the receiver is stamped "23A", and the left rear side of the buttstock is stamped "10 B". It has an all blue/black metal finish with an oil finished walnut pump handle and buttstock. It is fitted with the original four-hole heat shield/handguard with the correct bayonet lug on the front end designed for the M5A1 bayonet. It is fitted with the original factory sling swivels and currently has a commercial leather sling.