My bad. I just logged in and noticed the "no explosives" rule. Sorry about that. Ok, so fill the bottle full of water and plug it with a wooden dowl, rubber plug, etc. It would be heavier seeing how gas is about 6.8 pounds per gallon, and water is 8.6 pounds per gallon. The whole reason for making s...

(First post ever) WARNING: The following text is for informational use only. Building one of these devices could get you invited to the Graybar Motel. Several years ago, a friend and I were pondering the idea of using 20oz Coke bottles for a pneumatic mortar. For long range, stability of the bottle ...