I did not realize that the dual magazine bullpup shotgun concept goes as far back as the 1970s. John W. Winter produced a bullpup shotgun called the Winter SWATriplex-18 back in the late 70s. It could feed from either one, or both, of its 9 round magazines.

PT-The Italian Commie wrote at SecurityArms forum …

Consortium W (Winter) SWATriplex-18 prototype 12-gauge semi-automatic combat shotgun

Designed in the late 1970s specifically as a combat shotgun by John W Winter, the SWATriplex-18 had a number of unusual features, some of which appeared in later shotguns. Unfortunately, the company which was supposed to manufacture the weapon (Consortium W), pulled out after only a few prototypes were built and Winter was never able to attract anyone else to manufacture, let alone buy his unusual shotgun.

The SWATriplex-18 used a semi-bullpup design using twin tubular magazines under a single barrel. Feed could be from one magazine at a time, or alternately between the right and left magazines. Operation was semiautomatic, using gas operation and something quite unusual in a shotgun, a telescoping bolt. Construction was with a combination of light alloys and steel (for the barrel and where strength was critical). The 22-inch barrel was surrounded by a shroud/handguard which was ventilated for cooling. The SWATriplex-18 has ejection ports on both sides of the weapon; each could be sealed, and this allowed use of the weapon by both left and right-handed shooters by simply reversing the ejection direction, charging handle, and cheek rest (something most designers of bullpup weapons seem to overlook). The SWATriplex-18 used rifle-type sights on raised stands; both were adjustable for elevation and windage by knobs. (The raised sights were thought of as a potential problem, and Winter reputedly was considering either removable sights or moving the sights down to the receiver itself.) The stock was of light alloy, but the butt was synthetic with a rubber recoil pad. The top of the receiver had a carrying handle which could be folded flat against the receiver if desired.

The SWATriplex-18 was most likely a design which was way ahead of its time; many companies thought it was simply too weird-looking to sell, despite its reliability and advanced features. This may have killed the SWATriplex-18 more than anything else. Unfortunately, even the prototypes seem to have disappeared, and examples of the weapon now exist only on paper. However, the SWATriplex-18 design can be credited of a modern spawning as can surely have been a source of inspiration for the South-African designers Tony Neophytou and Heyns Stead for their highly successful Truvelo NS-2000 “NeoStead” pump-action combat shotgun

I would not classify that the NeoStead as being highly successful. Does anyone know how many were produced and in what countries it was sold in?

[ Many thanks to Thaddeus for emailing me the link. ]