While Congress and the President and the NRA haggle over gun control laws, Defcad.org is distributing 3-D printing specs for guns and parts of guns.
Check the following video for a demonstration of a printed 30-round magazine for a semi-automatic weapon.
Update, April 1
It may be an April Fool joke, but the Defcad,org web site has a notice saying the site and domain name have been seized by the Federal Government and Grand Jury indictments were issued.
Their latest video, which is still up on YouTube, announces Defcad Search:
The video shows off some guns with 3D-printed parts, denounces the intellectual property and promises Defcad Search, a search engine with CAD files from which there will be no takedowns, ever.
Defcad.org has now released a complete, single shot pistol. You can read more about it in this Forbes article. Is this any more a threat than home made "zip" guns made from common hardware parts?
The State Department requested that Defcad stop distributing their pistol plans, which they did. However, they report that there had been over 100,000 downloads and a quick Google search turns up sites which are now offering copies. Once something is out, you cannot put it back.
Leland Yee, a California State Senator who is alarmed by 3D printing of guns, has called for regulations of 3D printers.
Moving away from the dark side -- Michigan Tech University is running a 3D printers for peace contest. It's your chance to win a 3D printer -- what would Mother Theresa have done with a smart printer?
The 3-D printed pistol is not yet ready for prime time. Matt Ratto, a professor at University of Toronto printed a handgun -- it took 27 hours, a fair amount of computer know-how, a $50,000 printer, and $300 worth of plastic. What will it cost in ten years?
Here is an article (with links) on a low-cost, open-source 3D metal printer from Michigan Technological University. It's a work in progress, but it is less expensive than off-the-shelf commercial plastic 3D printers.