hmm weirldy enough all discussions in here are about guns, ok well heres something i thought up, a bomb actually, havent tried it out yet since my parents wont let me get my hands on explosives but it should make quite a blast. Discuss this or any other type of handmade bomb, but dont test it anywhere near other people or animals, and dont use it as a terrorist weapon, and have fun ok here it is: ingredients: sodium metal, should be available at science supply stores, and is usually kept in oil since air humidity would just erode it away an old tennis ball thin glass pane, easiest would be just to get the glassmakers you get it from to cut it for you since its not the easiest thing to cut glass, you want a circular pane with the diameter of a tennis ball. try to get it as thin as possible aswell. method: ok, get a carpenters knife, or something else which can cut a tennis ball, and cut the ball into two halves. fill one half with water and superglue the glass pane onto it. make sure it doesnt leak put some sodium into the other half, preferable cut up into little pieces with the carpenters knife first, dont put in too much though since it takes more water than sodium for this to work. then superglue the other half onto this one. and voila. A ... well .. almost normal looking tennis ball. fire away, and on impact with something hard it should blow up. and experiment with it. for example wrapping the sodium in tissue paper before putting it in may work better, and at least more slowly. and perhaps glueing the pane on the inside of the ball so when the glass breaks the ball is still intact, this would better ensure the water and sodium meet.