A really powerful homemade railgun, fired at some household items. The power (for a homemade railgun) is incredible, and while it doesn't compare to some military projects out there, it is pretty cool! Too bad the vid is so short Enjoy!

A gauss gun, works by sequentially accelerating a projectile to a desired speed by using either magnets or coils. The first video is a small demonstration of the principle behind the whole thing, by using magnets. The following videos are weapons which were homemade, and as you can see work remarkably well. So well in fact, that the US Navy will implement such weapons on its ships by 2020, after they succesfully tested an 8 Megajoule prototype.