Popular Science's John Robb reports on a person who claims that his 3D-printed pistol can successfully fire live ammunition, though not with total reliability. The same person then went on to print a working AR-15 rifle (this is a substantial advance on last year's account of a 3D printable AR-15 automatic conversion kit. This event has raised something of a crisis for Thingiverse, the online repository for 3D printable meshes, which is contemplating whether it will host files that can be printed into "weapons."

An amateur gunsmith, operating under the handle of "HaveBlue" (incidentally, "Have Blue" is the codename that was used for the prototype stealth fighter that became the Lockheed F-117), announced recently in online forums that he had successfully printed a serviceable .22 caliber pistol.

Despite predictions of disaster, the pistol worked. It successfully fired 200 rounds in testing.

HaveBlue then decided to push the limits of what was possible and use his printer to make an AR-15 rifle. To do this, he downloaded plans for an AR-15 in the Solidworks file format from a site called CNCGunsmith.com. After some small modifications to the design, he fed about $30 of ABS plastic feedstock into his late-model Stratasys printer. The result was a functional AR-15 rifle. Early testing shows that it works, although it still has some minor feed and extraction problems to be worked out.