Backyard BallisticsBy ellens81,01228 Suggested Projects Easy-Peasy PVC Water Gunby seamster in Toys & GamesAir Powered Potato Cannonby Hermes in BackyardEasy to Build, Easy to Use, Water Bottle Launcher!by bpwagner in RocketsViking Catapultby WoodsRunner in SurvivalChopsticks Catapultby BettyLee in Pranks, Tricks, & HumorHave an instructable you think should be included in this collection?SubmitSuccess!