Just watched a National Geographic program on hunters in jungles of Laos. They were using percussion muskets made locally. Halfstocks with long barrels. The barrels were blued and did not look like plumbing pipe, but who knows? The locks were interesting - the hammer was at a right angle to the breech, and swung horizontally. They used red plastic toy caps for percussion caps. The local gunsmith also made their black powder, apparently worked OK. They shot some small game with shot loads then killed a wild pig, probably loaded that round with a solid ball. They said their country is littered with old bombs and other scrap metal from the Vietnam War that they use for raw material for gun parts.