John Anderson’s Jackhammer
Michael Heidler explores a little known automatic shotgun that eventually found fame in a video game
Shotguns had proven to be effective close combat weapons in World War I. They are easy to use and powerful at short range in trenches and house fighting. But what if you had an automatic version?
Shotguns had proven to be effective close combat weapons in World War I. They were easy to use and powerful at short range in trenches and house fighting. Even in Korea and Vietnam, they were put to great use. Pump guns can be manually operated quite quickly, but an automatic mode would, of course, make them even more deadly. And so the idea of the Jackhammer was born. The person who came up with the concept was John A Anderson. He fought in Korea and quickly got to know the advantages of pump guns. During his time there, he always carried such a weapon with him. However, the manual reloading operation after each shot was too cumbersome and not fast enough in some turbulent close combat situations. An automatic weapon would have solved this problem so, in the early 1980s, Anderson devised plans for a modern, automatic shotgun. To realise the project, he founded the company, Pancor Industries in New Mexico.
By design, Anderson’s weapon resembles an oversized revolver with a 10-round revolving cylinder for 12-gauge (70mm) shotgun shells.
The operating principle is an unusual blow-forward type. This kind of mechanism is significantly simpler than the more common blow-back operated weapons. The barrel moves back and forth in a tubular jacket. At the moment of firing, a part of the gas pressure passes through a hole in the barrel into the cavity between the
barrel and the jacket. A sealing disk with rubber washer is attached around the barrel and the expanding gas in the cavity pushes this disk together with the barrel forward. As the barrel moves forward, the breech clears the front of the fired cartridge and an operating rod attached to the barrel rotates the cylinder through a zig-zag cam arrangement, very similar to the Webley-Fosbery Automatic Revolver. As the next shell aligns with the bore, the barrel returns under spring pressure back into the front end of the cylinder. The weapon is immediately ready for firing again. The operator can switch between semi-automatic and fully automatic fire by way of a thumb safety. The theoretical rate of fire is
240 rounds per minute. Spent shells are retained in the cylinder, as in a traditional revolver.
For loading and cocking, the foreend is pushed back and forth quite classically. An additional hook-style cocking lever is located in a cut-out of the buttstock to recock the firing mechanism if necessary. In this case the cylinder does not rotate. In ready to fire state a cartridge is in the upper chamber of the cylinder.
The tapered barrel slides about 1cm into the chamber until it stops at a circumferential step directly in front of the cartridge. That way, a very good gas sealing is achieved. Anderson had provided the delivery of filled, readyto-use plastic cylinders that were sealed against environmental influences. They would have been a cheap disposable item. Environmental protection wasn’t very important at that time.
Anderson hoped for strong interest from the government. He first made three prototypes by hand, which he sent to the United States
Department of Defense in 1984 for further examination. From there, the weapons were passed on to HP White Laboratories for extensive endurance and hardness testing. These tests were so thorough that two of the three weapons did not survive them. In the aftermath Pancor Industries made several models of wood, to demonstrate the mechanism to potential buyers.
The gun attracted attention and some foreign governments, such as Australia, Thailand, the United Kingdom, Qatar and Switzerland ordered informational material about it. But by now the coffers of Pancor Industries were empty. On one hand there was not even enough money left for the production of weapons capable of live-firing and on the other hand the Ministry of Foreign Affairs would not give the green light for export negotiations. As long as the weapon was officially still
in the testing phase of the American armed forces and no decision had been made, exporting wasn’t allowed. In 1987, Anderson patented his developments for all cases and only a short time later, Pancor Industries had to file for bankruptcy.
The only surviving example of the Jackhammer is the third weapon from the trials. In order to save weight, the two destroyed models had numerous sheet metal parts and components made of Rynite, an UV-resistant polymer from DUPONT. However, the third model is mainly made of metal and survived the test series almost unscathed. It has also fired a series of 50,000 low brass shotgun shells. The reloading procedures (after all, five thousand times) should have been quite annoying, because there is no device for a quick change of the cylinder. First, the stock and a few more small parts must be removed, then the axis of the cylinder can be pulled out to free the cylinder. The most important tool for this is an Allen key for the hexagon socket screws, with which most parts of the weapon are held together. But one should not forget that his model was a prototype and that this point would have surely been improved for a series production. Likewise, the fore-end was smooth and did not provide good grip for the shooter’s hand. The ribbed coating is not original, but a later owner of the weapon attached the hand guard of the suppressed Heckler & Koch MP 5 SD.
Incidentally, Anderson had planned another use for his cylinder designs. Under the name Bear Trap he developed a device in which a filled cylinder could be used as an anti-personnel mine. The bottom plate had 10 springloaded firing pins. In the simple version, all 10 rounds were simultaneously discharged by the weight of a soldier stepping on it. In the somewhat more elaborate version, a wind-up clockwork was installed and the spring-loaded timer could be set to trigger firing up to 12 hours later, in one hour intervals. This was to confuse the enemy and disrupt his supply routes. However, it is unclear whether these devices were actually built and tested.
In the liquidation of Pancor
Industries John Anderson took over the last surviving weapon and sold it many years later to a collector. After the disappointing experiences with the bureaucracy he turned his back on weapons technology. Without financial support and without good connections, he had no chance in this market.
All of which makes it more astonishing that today there is name recognition of the Jackhammer in video games. The futuristic appearance of the weapon was to give it a second life in first person shooters. In games like Far Cry or Fallout you can blow away enemies extremely effectively. The real thing was offered by Morphy Auctions (USA) in its October 2019 firearms auction for a minimum bid of $50.000, but it didn’t find a new owner at that time.