This is a 72 caliber under hammer in the works. Still need to put sights on it. It has Forsyth rifling with a twist rate about 1 in 32, 11.5" of rifled barrel. Weight is 5 pounds but I may take a little of the barrel length as it seems to be muzzle heavy. The ball above the barrel is .710, the other one is .457 for comparison. And that's a 1911 below. Plan is to start with about 20 grains of powder and work up slow. Last one I made took two hands at 45 grains shooting a hollow base wad cutter that looked like a small chainsaw piston and weighed over 600 grains.