Black powder, model rocket igniters, and ball bearings shoved into a piece of threaded pipe that’s capped on one end. You can build one of these in less than 30 minutes.
Hardest thing to get in Japan would probably be the black powder and it’s completely possible to manufacture that yourself. Everything else comes from the plumbing aisle of a DIY store and a model rocket shop.
Black powder, model rocket igniters, and ball bearings shoved into a piece of threaded pipe that’s capped on one end. You can build one of these in less than 30 minutes.
Hardest thing to get in Japan would probably be the black powder and it’s completely possible to manufacture that yourself. Everything else comes from the plumbing aisle of a DIY store and a model rocket shop.