The evolution of the 3D-printed gun continues. A Wisconsin man has improved on the original "Liberator" design released by Defense Distributed, bringing the cost down to $25.

The "Lulz Liberator" requires only a consumer grade 3D printer, in this case a $1,725 Lulzbot A0-101, not the $8,000 industrial 3D printer used to produce the original.

And the Lulz Liberator fires multiple shots. The original gun's barrel could only withstand the stresses of a single bullet fired from the chamber before needing to be replaced. The new design was fired eight times without exploding or breaking, though there were several misfire attempts.

The Lulz model contains more metal than the original, which only had a metal firing pin, and the addition of an extra piece of steel prevents it from slipping through a metal detector, as required by law. The ammunition cartridges also become jammed between shots and must be removed with a hammer, so rapid firing isn't possible.

The U.S. State Department demanded that Defense Distributed, remove the blueprints from its Defcad hosting site. Defense Distributed claims it has the right to release the files into the public domain, but it complied with the government request, though not before 100,000 people had already downloaded the files.

And it seems at least one of those people thinks the blueprints should still be available. It's important to note that The Pirate Bay doesn't host any files; it simply acts as an online tracker that locates those files and enables an easy peer-to-peer download. The files still reside on individual computers connected to the internet. Any of those computers located within U.S. jurisdiction could be subject to seizure, and their owners could be prosecuted for possession of contraband, assuming the authorities can locate them.

Some gun rights advocates claim fears of printed firearms are overblown. But obviously, the technology is advancing and becoming cheaper, smaller and more refined. The Liberator is only good for a single shot before the parts wear down, but new materials like carbon fiber and plastic composites could provide cheap alternatives for private gun manufacturers.

"Joe," the designer of the Lulz gun, and his partner Michael Guslick weren't required to announce their creation. It's very possible that other modified versions of the Liberator are currently being built around the world.

And in the space of a few weeks, the technology progressed from single shot to multiple shot, and the price dropped exponentially. Very soon, it may be cheaper and easier to print an untraceable, undetectable plastic gun than to purchase a real one, even off the black market.

In addition, new reports say gun enthusiasts are testing 3D-printed bullets. The time of metal detectors and useful gun regulations may be coming to an end.