Pancor Jackhammer

Pancor Jackhammer Mk3-A2 mockup

Pancor Jackhammer toolroom prototype with MP5SD handguard - 12 gauge.

Pancor Jackhammer toolroom prototype in original configuration - 12 gauge

The Jackhammer is a bullpup automatic shotgun which never entered production, using a revolver-style detachable cylinder (referred to as a "cassette") with a rotating action similar to the British Webley-Fosbery Automatic Revolver, and a gas-seal system similar to that of the Nagant Revolver, though with the barrel moving back to form the seal instead of the cylinder moving forward. A forward-back pump-action forend is used to cock the weapon initially, after which it indexes automatically. The mechanism is indexed by a cam on an operating rod attached to the barrel, which moves in a zig-zag groove to rotate the cylinder to the next chamber with each forward-back motion. The barrel is blown forward by gas tapped from the bore and returned under spring pressure.

It is often seen in video games as a "super shotgun;" the Jackhammer's popularity is due, in large part, to the futuristic look of the weapon, and is sometimes mistakenly described as the only fully automatic shotgun in existence. There is an element of unreality in featuring the Jackhammer in any context, as the weapon never made it past prototype stage; only two guns capable of firing in fully automatic mode were ever made. The real guns had problems with cassette grooves needing to be manufactured to extremely tight tolerances for the weapon to cycle correctly; typically, the full-auto guns could only manage two or three shots sequentially before failing to cycle. The weapon's design was also cumbersome and uncomfortable to shoot. A well-known fact is that more Jackhammers have appeared in any given work of fiction than ever existed in real life.

One unique feature was that the ammunition cassette could theoretically be combined with an additional assembly containing an array of strikers and a pressure plate to turn it into an ersatz landmine, referred to as the "bear trap." The precise utility of this is debatable since the plate was almost as large as another cassette and the "mine" would expend ten rounds to kill one person, even if it was guaranteed someone would actually stand on it. Regardless, only plastic mockups were ever made in order to test the mechanical workings, and no fully functional examples ever existed. Some sources also state that the magazine came loaded and was sealed at the factory meaning that it could not be reloaded with standard shells, however any remaining examples of this Jackhammer are loaded from standard 2 3/4" 12 gauge shells so this idea appears to not have been implemented. Even if this device were implemented and adopted, the 1997 Ottawa Treaty and the voluntary US ban on "persistent" landmines would have soon brought an end to it.

Two pre-production weapons were subject to full destructive testing, and just one functional Jackhammer remains in existence, a heavy toolroom prototype with a cylinder which accepts standard 12 gauge shells. This is not the final version, and among other things requires that the weapon be almost completely dismantled in order to reload it. For a time this weapon was owned by designer John Anderson; it was later sold to a movie armourer and fitted with the handguard grip of an MP5SD since the original smooth forend was thought to be too slick to reliably operate. This modification has followed to certain videogame renditions of the Jackhammer as the weapon has been used as a reference piece. The weapon is currently registered to a collector in New York.

After initial military testing, John Anderson continued development of the Jackhammer into the Mk3-A2 version. This model is the one that most often appears in media, despite being even less "real" than the original. It can be most easily identified by the sight rib, which rather than being a relatively flimsy stamped piece, is now a single piece aluminium casting with a distinct pattern of lightening cuts with a long slot with three circular holes. Only a single example of the Mk3-A2 is known to exist today and is an unfinished non-functional example lacking several key internal components. However, it is legally registered as a machine gun, and would be legal to build into a fully automatic firing example if its owner decided so.

The Pancor Jackhammer can be seen in the following video games:

Specifications

(Designed in 1984 and patented 1987, never produced)

• Type: Shotgun

• Caliber: 12 gauge pre-loaded (production), standard 12 gauge (prototype)

• Weight: 10.1 lbs (4.57 kg), about 14 pounds for toolroom prototype

• Length: 31 in (78.7 cm)

• Barrel length: 20.7 in (52.5 cm)

• Capacity: 10 round pre-loaded ammunition cassette (production), 10-round revolver cylinder (prototype)

• Fire Modes: Semi / Full-Auto

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Video Games

Game Title	Appears as	Mods	Notation	Release Date
Fallout 2				1998
Delta Force: Land Warrior				2000
Project IGI: I'm Going In			Incorrect 12-round capacity	2000
Max Payne			Incorrect 12-round capacity	2001
Fallout Tactics				2001
The Sum Of All Fears	12ga Auto SG			2002
Project IGI 2: Covert Strike			Incorrect 12-round capacity	2003
Rainbow Six 3: Iron Wrath				2003
Söldner: Secret Wars				2004
Far Cry				2004
Battlefield 2			Incorrect 7-round capacity	2005
Deadhunt				2005
El Matador				2006
The Darkness			Incorrect 64-round (!) capacity	2007
Cross Fire	"Jackhammer"		Pre-production model	2007
7.62 High Calibre	Jachhammer Mk3A2	w/ optional suppressor		2008
Battlefield Play4Free	MK3A1			2011
Battlefield 3	MK3A1		Back to Karkand expansion, incorrect 8 and 12-round capacities	2011
Warface	Piledriver			2013
Survarium			Version with MP5SD handguard	2013
Ghost Recon: Phantoms	M3A1	shown with railed top		2014
Modern Combat 5		With a front magazine.		2014
World of Guns: Gun Disassembly	Pancor Jackhammer			2014
Counter-Strike Online	PJ Mk3A1	10 round mag		2015
Hot Dogs, Horseshoes & Hand Grenades	"Jackhammer"		Version with MP5SD handguard	2016
Ironsight	Jackhammer			2018