Use two pipes, a length of 3/4" galvanized and a shorter length of 1" galvanized. A 12 gauge shotgun shell will fit in the inner diameter of regular 3/4" pipe. Endcap on the 1" pipe with a centered hole and a sharpened screw through it. One handle hose clamped to each length of pipe at right angles.
Stick the shell in the end of the 3/4", slide it into the 1", bring both halves together smartly and off it goes bang. Hopefully while your personage remains intact.
Exactly like it sounds from the name: You slap the cap containing the nail against the cartridge.
There are certainly better and slightly safer designs for this sort of thing, which aren’t much more difficult to construct.
Such as?
I’m curious.
Use two pipes, a length of 3/4" galvanized and a shorter length of 1" galvanized. A 12 gauge shotgun shell will fit in the inner diameter of regular 3/4" pipe. Endcap on the 1" pipe with a centered hole and a sharpened screw through it. One handle hose clamped to each length of pipe at right angles.
Stick the shell in the end of the 3/4", slide it into the 1", bring both halves together smartly and off it goes bang. Hopefully while your personage remains intact.
https://www.forgottenweapons.com/a-vet-returns-to-civilian-life-richardson-industries-slamfire-guerrilla-shotguns/