Railguns were once the domain of science fiction and video games, but that has changed over the last few years with the US military working hard on developing railguns for ships and even vehicles. While this sort of weapon is still a ways from being field ready, a geek called Ziggy Zee has built his own man portable railgun from scratch.
He didn’t use 3D printing for any of the components needed to build the weapons, which can shoot projectiles with 27,000 joules of force, or about 950 pounds of force. That is certainly enough to cause major damage to people and objects in front of the rail gun.
The way the railgun works is that the 22g aluminum projectile is first accelerated to 50mph using CO2 as the propellant. That slug then passes through a pair of copper rails that have 46 480-joule capacitors that discharge and force the projectile from the muzzle. Those capacitors are charged by a 400V power source.
The force of acceleration is so strong that part of the projectile melts on its way down the muzzle. It’s almost scary that the builder has posts that illustrate the process used so that others can replicate it. The video of the railgun in action is worth a watch.