Pancor Jackhammer
Pancor Corporation · Shotgun · Prototype · 1987
Also known as: Jackhammer Mk3, Jackhammer Mk3-A2, Pancor Mk3 Close Assault Weapon System
Overview
The Pancor Jackhammer is a 12-gauge bullpup automatic combat shotgun designed by John A. Anderson of Pancor Corporation in Las Cruces, New Mexico. Designed in 1984 and patented in 1987, the Jackhammer used a highly unusual gas-operated blow-forward action: gas tapped from the barrel drove the entire barrel forward away from a stationary 10-round revolving 'ammo cassette,' clearing the spent shell and rotating the cassette via zig-zag cam grooves before a return spring drove the barrel back into battery on the next round. The bullpup layout placed the cassette behind the trigger, putting most of the gun's mass between the shooter's hands and giving a 525mm barrel within an overall length of just 787mm. The cassette itself was treated as a disposable ammunition pack - reloading meant swapping an entire pre-loaded cylinder rather than individual shells. The weapon could fire in semi-automatic or full-automatic at a cyclic rate of approximately 240 rounds per minute. Many parts were moulded from DuPont Rynite polymer to keep weight to 7.9 kg unloaded. Despite extensive military and law enforcement interest from agencies in the late 1980s, the Jackhammer was crushed by a combination of the 1986 Hughes Amendment (which banned new civilian transferable machine guns), the high cost of tooling up production, and an inability to secure a foreign launch contract. Only three working prototypes were ever built; two were destroyed during destructive testing at HP White Labs and just one survives.
Specifications
| Weight (empty) | 7900 g (278.7 oz) |
| Overall Length | 787 mm (30.98") |
| Barrel Length | 525 mm (20.67") |
| Action Type | Gas Operated |
| Firing Mechanism | Striker Fired |
| Trigger Type | Single Stage |
| Magazine Capacity | 10 rounds |
| Magazine Type | Rotary |
| Muzzle Velocity | 400 m/s (1312 fps) |
| Muzzle Energy | 2240 J (1652 ft·lbf) |
| Effective Range | 50 m (55 yd) |
| Maximum Range | 150 m (164 yd) |
| Rate of Fire | 240 rpm |
| Barrel Rifling | None |
| Number of Grooves | 0 |
| Frame Material | Polymer |
| Slide Material | Steel |
| Barrel Material | Steel |
| Stock Material | Polymer |
| Finish | Matte Black |
Calibers
- 12 Gauge · primary — also known as 12 ga, 12 bore, 18.53mm bore
Features
- Firing modes: Semi Automatic, Full Automatic
- Feed systems: 10 Round Revolving Cassette Magazine
- Safety mechanisms: Selector Switch, Manual Safety
- Features: Bullpup Layout, Blow Forward Barrel Action, 10 Round Disposable Revolving Ammo Cassette, Select Fire Full Auto, Rynite Polymer Construction, Zig Zag Cylinder Cam, Iron Sights, Cassette Convertible To Bear Trap Mine
Variants
- Pancor Jackhammer Mk2 (early prototype) — Prototype
- Pancor Jackhammer Mk3 (definitive prototype) — Prototype
- Pancor Bear Trap (BMF cassette anti-personnel mine) — Accessory Mine
Production
Estimated total produced: 3 · Production years: 1984-1994
Only three working prototypes were ever assembled. Two were destroyed in destructive testing at HP White Labs in the late 1980s. A single surviving example exists and is registered as a transferable Title II machine gun in the United States.
Origin
Country of origin: United States
Designer: John A. Anderson
Discontinued: 1994
Notes
An additional design feature of the Jackhammer was the 'Bear Trap' (or BMF) accessory: a loaded ammunition cassette could be detached from the gun and fitted with a separate firing mechanism to function as an improvised anti-personnel mine, triggered by either a pressure plate or a spring-loaded timer of up to twelve hours. Whether functional Bear Trap units were ever built is disputed - Pancor literature shows them, but several historians believe only the basic plastic mock-ups were ever assembled. The single surviving Mk3 prototype was sold at auction in 2020 and is registered as a transferable machine gun.
Background
Despite never being mass-produced, the Pancor Jackhammer became one of the most recognisable fictional firearms of the 1990s and 2000s, appearing in dozens of films, television shows, and video games - from the original Total Recall to Counter-Strike, Far Cry, and Resident Evil - almost always portrayed firing far faster and more accurately than the real prototype ever managed. The single surviving Mk3 Jackhammer is one of the most valuable transferable machine guns in private hands; in 2020 it sold at Morphy Auctions for over USD $130,000. Designer John Anderson was a Korean War veteran who had grown frustrated with how slowly pump-action shotguns could be reloaded under stress.