I wish I would have joined before I made the cannon. I did practice shooting crossbow bolts out of it with good results. I did notice however the shorter the bolt the more accurate it was to my surprise. I was told that I could get pure oxygen here but have yet to find it. Have you ever used it befo...

thanks alot for the idea. I will make one like you suggest. I just figured if I kept a big chamber, reduced the barrel size it would shoot better but it doesn't seem to be the case.

I live on a 3 mile island and to say its space would be an understatement. The closest real hardware store is either a plan ride or 6 hour boat shuttle. I was hoping to find some oxygen but it is proving more difficult than I thought.

So Im from the states and live on a small island in the middle of the Taiwan straight where it is illegal to own or possess a firearm. I made a spud gun with a 3.5 inch combustion chamber that is about 16 inch long and reduces to a small pvc barrel that shoots standard marbles. The problem is that h...