The incredible, printed assault rifle. It's not just good for six rounds any more.
Now the whole gun isn't made through 3D printing. The barrel, for example, is a true, metal component. That doesn't matter. Barrels are just a machined, metal tube. What is important is the "receiver" or the "action." They're the moving parts that load bullets into the barrel, fire them and eject spent casings before reloading. That's the guts of a modern instrument of mass mayhem and that's what you can produce with 3D printing.
The first attempt lasted just 6-rounds. The new and improved model in this video fired 600-rounds. Christ on a crutch!