There you have it - one functioning air cannon. You can hold them in your hand to fire them - the recoil isn't bad at all. If you choose to use it this way, you'll want to duct tape a little block of wood (like a 1x2) between the barrel and the air chamber to keep 'em from banging around. I like to mount these on carriages to give the 'feel' of a real cannon. Building the carriage and mounting the cannon is another essay itself. PVC degrades in sunlight so you'll want to paint it. Regular spray paint works fine.