As sickipedia said, it's cheaper to buy an AK47 than to buy the HP cartridges to print your own.
Erm...it's Sickipedia. I don't think anything there should be taken seriously. ;)
Like @plexer says this changes nothing...
The first non-prototype-metal printer I could find US$ 750,000 approx. There are cheaper metal printers but these cant print in stainless steel only a cheaper weaker alloy.
Plus materials/power/misc = $5,000
So thats $755,000 or £471,573.20 BEFORE you even start to print.
Lets assume (big assumption as I have no idea if this is true) you can buy a hand gun for £100.
Hmmmmm everybody panic, criminals can print guns!!
I imagine a box of fireworks (£10ish), a steel tube (£5 at most) and some fishing shot (£2) could make you a pretty deadly shotgun. I'm not going to lose any sleep over this "news"