I have an old military rifle barrel section that slugs just over .312. It is a fairly fast twist and I can get a little over 12" of useable barrel. Would like to make a single shot. 32 caliber side or under hammer handgun. Is there any reason not to use one of these barrels to make a muzzle loading handgun? Probably a dumb question but when I don't know I ask. Was told no but the guy couldn't explain why not? Thanks for any replys.