If an atomic zombie is molesting you, get this coil gun, aim with its built-in laser gun sight and pew-pew a metal projectile at 110km/h into his rotting cranium, with a total energy of 18 joules.
Don't count on holding an invasion of them, though. The coil gun—which uses electromagnetic coils configured as a synchronous linear electric motor, accelerating fire metal pieces as it goes through it—needs eight seconds to have enough electric charge. And that's while plugged to the wall. With batteries, it's 90 seconds.
That said, it's quite impressive, knowing that it only took its creator, Daniel Eindhoven, 40 hours to make it. I want. [The Contaminated]