Last month, Austin-based Defense Distributed was granted a Type 7 federal firearms license. The not-for-profit group of 3D-printing enthusiasts and gunsmiths had been designing and printing weapon components for a while (including AR lower receivers, the portion of an AR legally considered to be the "body" of the firearm), but the federal firearms license enabled them to legally manufacture and distribute "lowers" and other weapons, with some stipulations.

Today, though, Forbes is reporting that the folks at Defense Distributed have gone beyond merely designing and printing weapon components, and have instead created an entire weapon: the "Liberator." It's an unassuming little thing, looking a whole lot like something from the toy aisle at Wal-Mart, but it fires real bullets—in fact, it even features an interchangeable barrel so that it can handle different caliber rounds.

According to Forbes, Defense Distributed will soon be running the weapon through a full set of tests to determine its reliability and durability, similar to how it previously tested its AR receiver and magazines. Once this has been done, the design will be made available on Defense Distributed's website for the public to download and print.

The Liberator pistol isn't all 3D printed ABS plastic, though. There are two bits of metal within the design: the first is a nail, which serves as the firing pin (producing a firing pin out of plastic is a difficult proposition). The second is a 6-ounce steel slug, used to ensure the weapon can be picked up by metal detectors as required by the Undetectable Firearms Act of 1998.

Of course, when the plans are made available for home use, nothing would stop a would-be Mitch Leary from omitting the slug to make the gun "undetectable" (though there would still be the problem of making the bullets undetectable). The prospect of wide-spread 3D handgun printing already has at least one congressman, Steve Israel (D-NY), up in arms to extend and expand the Undetectable Firearms Act to ensure that it covers magazines and other 3D printed components, which would handily squash the "Liberator" and any of its derivatives:

The revamped Undetectable Firearms Act that Rep. Israel wrote makes it illegal to manufacture, own, transport, buy, or sell any firearm, receiver, or magazine that is homemade and not detectable by metal detector and/or does not present an accurate image when put through an x-ray machine.

On one hand, it's difficult to envision a practical use-case for a 3D printed firearm, since producing one requires that you own a relatively expensive 3D printer. If you're a US citizen and you're just aiming to have a handgun, it would be far more convenient and affordable to simply amble on down to a place that sells them and buy one. However, there are a growing number of folks concerned that citizen access to firearms will grow progressively more difficult over the next few years and who might be keenly interested in the ability to produce their own, without having to rely on the consent of the government. Indeed, Defense Distributed's reason for existing is to ensure that people can do just that:

The specific purposes for which this corporation is organized are: To defend the civil liberty of popular access to arms as guaranteed by the United States Constitution and affirmed by the United States Supreme Court, through facilitating global access to, and the collaborative production of, information and knowledge related to the 3D printing of arms; and to publish and distribute, at no cost to the public, such information and knowledge in promotion of the public interest.

"Everyone talks about the 3D printing revolution," Defense Distributed's Cody Wilson told Forbes. "Well, what did you think would happen when everyone has the means of production? I'm interested to see what the potential for this tool really is."