Air Cannon

I made a new toy... A few years back I made two spud guns which were powered by aerosol and a spark, but they weren't powerful enough for my taste. So... I made a new one! This "air cannon" is powered by pressurized air. The tank holds around 140 psi which is incredibly powerful. Once the tank is filled up I put a wad in it and place any item that I want to fire out of it. It shoots anything that fits in the barrel. rocks...spears...water...sand...flour...golf balls..you get the idea. Here's where it gets good! Last nite I was in my back yard and saw a duck fly into our pond. I filled up my gun will about 10-15 small rocks and shot it! Nathaniel was there with me to witness this glorious event. After we killed it we prepared it and ate it. hahaha!! but seriously.. pretty sure I scored a few man points for making a weapon that killed a duck and then for eating it afterwards.