ya sorry i wasnt around yesterday... I have 2 cannons, both compressed air powered. dubbed the SPNKr and the SPNKr II... one has a 1 1/2 inch barrel, and the other one has a 2 1/2 inch barrel...perfect for tennis and lacrosse balls. One day I happened to shoot a bottle filled with water out of it, and it hit my neighbors shed from about 50 yards away... it hit right at the hinge of the door, blew through the siding, the 3/4 inch plywood, and the 2x4 at the end of the door! Ive also shot tennis balls into an electrical transformer, only to have the tennis ball bounce a block down the street. it leaves an oval shaped imprint and the fizzes are embedded into the metal now! my next task is to destroy a nalgene water bottle with it! will post pics when i can