really? they didn't have machining in the 1700s. how about a good'ol musket? or a bit more modern: a gatling gun. I always thought those were made under coarse conditions. I mean, people just need something that makes a spark against gun powder,goes boom and shoots really fast projectiles. If a shotgun is possible, then an automatic shotgun doesn't feel like it's a stretch. I would think the firing mechanisms might not be tolerant of amateur techniques, but the reloading and trigger parts at least might be. I'm also not a gunsmith, no idea what I'm talking about for the record.