This homemade gun uses electromagnetic coils to send steel rods flying at a speed of 138 feet per second. Pressing the trigger loads a steel rod into the barrel, where the first electromagnetic coil pulls the rod forward via magnetism, then turns off. The next coil is triggered on by an infrared sensor, propelling the rod farther down the barrel, and then so on and so on until the projectile flies out with a thwuck!
Here’s a gif showing how that process works:
Coilguns are an interesting concept, and this one, created by Jason Murray of Delta-V Engineering, is certainly effective at destroying empty cans, a laptop screen, and a slice of cake. Murray should totally get together with that record-breaking slingshot dude.