|Pancor Jackhammer Mark 3-A2|
1987 Patent of the Jackhammer machine shotgun
|Place of origin||USA|
|Barrel length||525 mm|
|Cartridge||12 (2¾") gauge|
|Action||Gas-operated, automatic shotgun|
|Rate of fire||240 rpm|
|Feed system||10-shot ammo cassette (also functions as an anti-personnel mine)|
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.
The firearm was designed by John Anderson of Pancor Industries in New Mexico. Reportedly, a number of foreign governments expressed interest in the design and even ordered initial production units once ready for delivery. However, the design was held up for production by the testing of the United States Department of Defense and the firearm design was eventually passed over in favor of existing 12 gauge weapons. The languishing of the design in administrative limbo caused Pancor to go bankrupt, as they could not fill foreign orders without the blessing of the State Department, and the State Department would not grant export licenses while it was being ostensibly tested by the Department of Defense. The assets of Pancor were sold off, including the few prototypes of the Jackhammer that were built.
Technical definitions 
The firearm, excluding the barrel, is constructed largely of a rynite plastic in order to reduce weight. It features a bullpup layout to preserve a 525 mm barrel length in an overall 787 mm package. The shotgun is fed by a 10-round capacity center-rotating drum using conventional 12-gauge cartridges. The shotgun weighs 4.57 kg and has a maximum rate of fire of 240 rpm. The drum's method of rotation is very similar to the Webley-Fosbery Semi-automatic revolver.
The floating barrel is driven forward by gas pressure from the fired round. The barrel is then returned by a spring and moves the drum operating rod, breaking the tight seal between the barrel and the drum to revolve. Spent cartridges are not ejected. Instead, they remain in the magazine.
Magazine function as an anti-personnel mine 
As an additional feature, it is possible to take the drum magazine off the firearm, attach a detonator, and use it as an anti-personnel mine that fires all of the cartridges at once when tripped. The manufacturer advertised this as the "Beartrap."
The Pancor Jackhammer is fully automatic and thus classified as a machine gun in the United States under the National Firearms Act (NFA) of 1934. As such, it is regulated by the Bureau of Alcohol, Tobacco, Firearms and Explosives.
Related developments 
- Webley Fosbery – Automatic revolver
- Steyr Mannlicher M1894 – Blow-Forward barrel
- Nagant M1895 – Gas seal
See also 
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