This homemade revolving shotgun design seems well suited for a 3D printed/hybrid metal manufacture. While the version pictured uses cut off chambers from cast off 12 gauge barrels, the same effect could be accomplished by using sections of the appropriately sized water/gas pipe or tubing. The same tubing/pipe could be used for the barrel. The concept would be that the 3D printed parts would comprise the cylinder into which the chambers would be fitted and glued, and which would have the more difficult mechanical details to revolve the cylinder . . .
Perhaps a modification of the zig-zag revolver design by Yoshitomo Imura would work. A metal frame created with the “sandwich” system, laminated of sheet metal, would provide the necessary tensile strengh, which is not very high for smoothbore shotgun cartridges in any case. The top or bottom of the frame would consist of a bolt that would form the axis for the cylinder to rotate on. A loading/ejection port would be left on one side to load cartridges into the chambers. A simple rod or dowel could be used to eject them.
Surprisingly, revolving shotguns seem to have less problems with cylinder/barrel gas leakage than other systems, perhaps because of the relatively low chamber pressures for shotgun shells.One of the attractions of this sort of hybrid system is that it uses commonly available materials. Shotgun shells are the most easily available ammunition in most countries, and a revolver design does not rely on ammunition consistency to work well, as do semi-automatic designs. Even crude home made ammunition, such as Russians used to make with ground up match heads as gunpowder, would work in this type of system.
A six shot revolving shotgun cylinder whose bulk is composed of ABS plastic should not be too heavy or cumbersome. The steel chamber inserts would contain the bulk of the pressure created by firing the cartridge. The steel frame would prevent the chamber inserts from moving forward or backward when firing, provide the necessary tensile strength, and the attachment point for the barrel. A small welder could simplify frame construction, but is not necessary.
©2014 by Dean Weingarten: Permission to share is granted when this notice is included.