wow this is a fancy one. the one friends & I built in high school was more simple 1) a narrow tube to put potato in 2) a larger tube for firing chamber with a

wow this is a fancy one. the one friends & I built in high school was more simple 1) a narrow tube to put potato in 2) a larger tube for firing chamber with a screw cap 3) a sealed hole cut into firing chamber for a lighter put potato in one end, unscrew the cap, spray hairspray liberally inside, screw cap back on, aim, and fire