The mainstream tech press are a buzz about a Arfcommer, HaveBlue, printing and successfully shooting an AR-15 with a 3D-printed lower receiver. He printed the lower using a slightly modified model from cncguns.com on a old Stratasys 3D printer.
HaveBlue is currently putting together a printed AR-10 on what looks like a DIY 3D printer.
[ Many thanks to Andrew & Seth for emailing us the link. ]