Hi all,
I'm a WWII reenactor and have been toying with the idea of how to create a safe demonstration round for our group's PIAT. For anyone not in the know, it was a spigot mortar that worked by cocking a big spring, an 8" piston went back inside. A bomb (think a big vortex football with a hollow tail) was put in the tray with a retaining disc at the back to line it up. When the trigger was pulled, the piston rammed up the tail and set off a charge that would send the bomb flying, the seal of the tail over piston acting as a "barrel in reverse"
Obviously anything close to an original concept would be prohibitively dangerous. I wanted to launch a foam football with a 3D printed tail segment. My original idea was to use a CO2 cartridge up in the nose in place of the original "charge" and a push pin to activate it when it gets smacked by the piston. https://imgur.com/a/mRgY6Dv However, I've run into some trouble getting the CO2 cartridge to activate and the rocket staying put long enough for the piston to slam home.
There is also the potential for that CO2 cart to become a wacky missile should this thing break up. AskEngineers over on Reddit suggested removing the piston from the equation and using something like a spud gun to launch it, put the hollow tail over the mini spud gun like a nerf dart and PEW.
The bottom of the PIAT tray has a window that I could run a hose or tubing up to a "barrel" pipe (after the PIAT is cocked an attached fin could sit in the slot for the original tail retainer. You "fire" the PIAT but actually just open a valve on the spud gun. The idea of PVC pressure chambers makes me very uncomfortable, I'd rather make it out of metal and weight and portability isn't really an issue. Is there a resource here for metal valves and tubing rated for the 800PSI a Paintball tank regulator puts out?