http://www.bbc.co.uk/news/technology-19813382

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This could be "fun"
Afterall once the printers do become more mainstream and assuming that torrents of printing plans are avaliable it will be impossible to stop anyone printing thier own gun. Ammo then becomes the issue.....hmmm Print a musket and then make your own black power

Already under discussion here - viewtopic.php?f=19&t=17335

Having seen some 3D printed stuff I find it hard to believe you could 3D print the breech of a gun that would actually withstand the force of any decent propellant being ignited. Maybe a something like metal sintering could do it, but with standard 3D printer plastics? You'll kill yourself much more likely than anyone else.

The titanium laser thingy would probably handle it, but you're probably better off (in terms of cost) buying something over the counter.
Unless you like Tony Stark or someone.
In which case you're Iron Man.

Anyway, it's 'Merica. Guns aren't exactly a rare commodity.

Email it in to Mythbuster. I'd love to see them test that!