3D-printed guns have been making the news a lot recently. That's not to say that they and their creators don't deserve the press — people arming themselves without so much as a permit is pretty terrifying. But whoever it was that said 3D printing was the only way for people to circumvent the law and arm themselves just might not have seen this bad boy.
This fully-automatic Gauss gun, dubbed the CG-42, has a 15-round capacity and can fire an entire clip of ammo in 1.5 seconds. What it fires is almost as frightening as the gun itself, because the CG-42 is armed with nails, side-stepping the need for even the slightest of paper trails.
Editor's Note: Find the directions and specifications here.