32 bore is .52 caliber. Brass will likely have to be turned, which is no real problem as it's most likely a short case. As for the pins and 'primers' that's no big deal either. I'm with Tinker - nice rifle and needs to be shot. A rather rapid twist it appears, close to a turn in the length of the tubes, therefore for short bullet. With light loads, a round ball would work just fine, full size or tightly patched. A fun gun to work with, for sure.