This is a real world Coil Gun. It uses electricity and I believe magnets to fire bullet like projectiles (made of magnetic material) at uncanny speeds.
Supposedly it can achieve a comparable velocity to that of a .45 handgun, but as Make points out this isn’t to be believed since this is probably the power emitted in the capacitor bank, but not at the actual muzzle. Probably a good analogy is the maximum horsepower of a car and how much is lost when attempted to transfer from tire to ground.
Anyway, this is one solid build that took two years to produce. Fortunately for us, they’ve produced a short film of the gun destroying some household goods. Enjoy.