Considering the tech level the mad scientists have here, and how we're completely ignoring the complexity of many other things, we might as well make smokeless powder out of wood.And then you'd have to gather the ingredients to make gunpowder. It would only take 20lbs of bird shit and/or bat shit to get enough potassium nitrate to make one bullet. Then you'd need sulfur which you can get from volcano's and charcoal.
Think of it - main characters can weave cloth by hand, with no loom or anything, almost instantly.