October 22-23, 2019 Extraordinary, Sporting & Collector Firearms
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This lot is closed for bidding. Bidding ended on 10/22/2019
This is an unbelievably rare piece of firearms history, with only three functional weapons ever being produced, and two of those were intentionally destroyed incidental to endurance testing by HP White Labs, leaving only this one. The MK3 fully automatic shotgun was developed by John Andersen based on his experiences during the Korean War, where he found that the pump action shotguns used by the military were difficult to load and took far too much time. His solution was the MK3, more popularly known as the Jackhammer. The Jackhammer cannibalized elements of various firearms and put them together to form a bullpup revolving select fire shotgun. The magazine is a cylinder with very distinct cuts reminiscent of the Webley-Fosbery and utilized a pin on the operating rod to rotate it. The barrel utilizes a tapered breech which sinks into the magazine, forming a gas seal similar to the Nagant revolver, that is broken by the firing sequence, where gas releases the barrel and blows it forward, allowing the operating rod pin the perform a half cycle to the next chamber, and then the recoil spring drives back, letting the operating rod pin complete the cycle to the next chamber and letting the barrel reseat in the cylinder, ready to fire again. The iron sights are a simple V-notch and post and mounted within the carrying handle. There is a five-vent muzzle brake attached over the end of the barrel that holds the recoil spring in place. Rear of drum housing with a small metal plaque reading “MANUFACTURED BY / (LOGO) / PAN ASSOCIATES / DENVER COLORADO 80200 / NO. JHMK3AI / 2.75 12 GAUGE ONLY”. This particular gun is most appropriately called a tool room prototype, and weighs more than 17 pounds, significantly heavier than guns provided to HP White. Additionally, this gun has operational idiosyncrasies that would never make it to a production gun; for example, replacement of the magazine requires partial disassembly, and many of the parts are made out of cast metal, explaining the heavy weight. This particular specimen is instantly recognizable as the owner who purchased it from Andersen replaced the forearm with a ribbed grip from an MP5SD and then rented the gun out to animation studios, movie studios, and others to utilize as a sci-fi looking weapon. Accompanying this gun are five additional recoil springs. CONDITION: Overall extremely fine, retaining the majority of its finish, with some marks from handling and operation. Selector switch has a distinct line between the three positions, and sections of the buttstock and the grips have rubbed to gray patina. Heavy machining marks are visible in some places, such as trigger and muzzle brake. There is a good-sized area on the muzzle brake that retains its black finish, but is now largely a silver patina. Magazine has a few areas of brassing and nicks from where the operation rod pin has hit it. There is one small area of added white paint in one of the channels. Mechanics are very good, somewhat soft. Bore is very good to excellent. Bolt face is very good. This is a once in a lifetime opportunity to own this shotgun, which is a machine gun and registered as such in the NFA registry, and if you are a collector of NFA items, interesting prototype weapons, or just famous guns, you cannot afford to miss this. THIS IS A NATIONAL FIREARMS ACT ITEM AND REQUIRES BATF APPROVAL PRIOR TO TRANSFER. THIS ITEM IS FULLY TRANSFERABLE ON AN ATF FORM 3 OR 4. EW
Five additional springs
Barrel Length
22 - 1/5"
12 Bore
FFL Status
Sear Serial Number
Serial Number
Current Bidding
Minimum Bid: $50,000.00
Final prices include buyers premium:
Estimate: $100,000 - $175,000
Number Bids: 1
Auction closed on Wednesday, October 23, 2019.
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