Can't you make a blunderbuss pretty easily with some rocks and scrap? I wonder how straight shooting a musket you could make? Probably pretty straight if you happened on something manufactured that already happens to fit pretty precise into your cylinder I'm guessing. You could probably get pretty far with airguns too. I mean a pellet gun is already enough to kill a bird or squirrel outright and pretty damn accurate. I probably wouldn't want to take one of those to the neck or soft part of the head.