I think the 32-40 and the .32 Win Spl were about .311 or .312. Are rimmed and power wise about 30-30. Barrel would have to be set back and the rims are smaller so that would be cause more work. They are shorter and slimmer so would not feed right without more work. The easiest would be a new barrel in 30-40 krag that would most likely be the least work. I'm sorry but I can see no merit in your idea at all. The only thing that rifle has going for it is the price of the gun and ammo.