Pancor Jackhammer
Summary
| Country | 🇺🇸 United States |
| Category | Combat shotgun |
| Manufacturer | Pancor Corporation |
Technical specifications
| Pancor Jackhammer | |
|---|---|
| Fire Rate | 240 rounds/min. |
| Caliber | 12 (19.5 x 76 mm) |
| Magazine | 10 rounds |
| Length | 787 mm (31.0 in) |
| Weight | 4.57 kg (10.1 lb) |
| Range | 40 m (131 ft) |
Description
The Pancor Corporation Jackhammer was a 12-gauge, blow-forward gas-operated bullpup automatic shotgun designed in 1984 and patented in 1987 by John A. Anderson of Pancor Industries. Anderson, a Korean War veteran, aimed to create a shotgun that improved upon the reloading speed of pump-action designs. Despite interest from foreign governments, only three working prototypes were built. Testing by HP White Labs resulted in the destruction of two prototypes, which may have featured design differences from the initial prototypes, including lighter materials and an altered reloading method. Dozens of non-functioning prototypes were also created for tool development, using materials like sheet tin, balsa wood, and clay.
The Jackhammer never entered production due to legal and financial difficulties. Export required United States Department of Defense testing, which led to its rejection. Civilian sales in the U.S. were prohibited because the firearm was classified as a machine gun under 1986 restrictions. Foreign governments that expressed interest did not provide the funding needed for development and production. Pancor declared bankruptcy and its assets, including the prototypes, were sold. One toolroom prototype is in technical firing condition but requires disassembly for reloading and has a different handguard. Another refined but non-functional prototype exists, legally registered as a machine gun. Both have been auctioned.
The Jackhammer can be described as a gas-operated revolver, using a bullpup layout and a 10-round revolving cylinder for 12-gauge shells. Weight reduction was achieved using Rynite polymer for many components. Cylinder rotation is similar to the Webley–Fosbery Automatic Revolver, employing an operating rod and a "zig-zag" cam arrangement, driven by gas pressure.
The shotgun offers semi-automatic and fully automatic firing modes, selected via a thumb safety/selector switch. When fired, gas tapped from the bore drives the barrel forward via a ring-piston, sealing the front of the shell within the cylinder breech. This movement clears the spent cartridge and rotates the cylinder using the operating rod and cam. The barrel then returns under spring pressure to engage the front of the cylinder. Spent shells remain in the cylinder, requiring manual extraction after cylinder removal from the bottom of the receiver. Reloading requires moving and securing the barrel forward before removing the cylinder. The weapon includes a charging handle in the forward grip and a cocking lever in the buttstock.
A unique capability was the "Bear Trap" conversion, enabling a loaded cylinder to function as an anti-personnel device with a firing mechanism activated by:
-
A pressure plate
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A plunger
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An adjustable timer
This discharges the shells. The cylinder is designed to contain firing pressure and is reusable. Sources differ on functional Bear Trap prototypes, some citing only plastic models, while others suggest full development.
The Jackhammer never progressed beyond the prototype phase, so there were no production variants. The firearm has no operational history with any military or law enforcement organizations, and was not formally adopted or fielded by any military forces.