Railguns, devices that use electromagnetic force to fire projectiles, are a staple of science fiction. They're the most powerful sniper style gun in the Quake series, the coolest weapon in SyFy's Dark Matter, and the nuke launcher on top of the mighty machines of the Metal Gear series. It's tech the world's militaries want on their side too. The U.S. Navy is working on a massive railgun meant to fire from ships, but the weapon is still years away from deployment.
In a YouTube video and an essay posted on Imgur, one intrepid engineer calling himself NSA_Listbot has done what was long a science fiction dream—he crafted a portable semi-automatic railgun. It's not perfect—the magazine only holds three rounds and he keeps a firing extinguisher on site in case something goes wrong—but users can hold the gun without support and fire three rounds with minimal effort.
NSA_Listbot crafted another railgun two years ago he called the XPR-1, but the beast was heavy and only fired one shot at a time. He had to prop it up to support its weight. The capacitors were the heaviest component and NSA_Listbot spent two years redesigning the gun with the idea of using more energy dense photoflash capacitors.
To be clear, this isn't the first homebrew railgun out there. Far from it. YouTube is full of homemade railguns of varying lethality and practicality. What sets NSA_Listbot's gun apart is that users can carry it themselves and it loads itself between shots
NSA_Listbot custom designed both the magazine and receiver and manufactured it himself (minus the spring) using a 3D printer. It's different than a traditional rifle in that the charging handle moves the feed mechanism automatically to load the next "bullet" into the chamber.
The gun charges to 4.5kJ before firing off a round. It takes a few minutes between shots to charge up and the tungsten, steel, aluminum, and plasma rounds don't do too much damage. In the videos, NSA_Listbot and his buddies make short work of melons, an old laptop, and a can of shaving cream but it's hard to imagine what exactly this weapon would do to flesh.
But hey, this is just a prototype. Improvements are surely on the way.