High Quality Content by WIKIPEDIA articles! The Pancor Corporation Jackhammer is a 12-gauge, gas-operated automatic shotgun. It is one of very few fully automatic shotguns, and although patented in 1987, it never entered full-scale production. Only a few working prototypes of the Jackhammer were ever built; some sources state that only two fully automatic prototypes exist. In the late 1990s, the current owner of the design, Mark III, attempted to sell the patents, prototypes, and production rights for $350,000. Nonetheless, its distinctive appearance and futuristic, stylish design have made it popular in action television programs, films, and video games.