so he only printed some of the gun. the upper casing is metal a component that is off the shelf. however, its only a matter of time before you can print a whole gun out of metal. Right now the personal know how to build a working 3D model of a gun, print it out, build it, and use it will be the biggest hurtle.
I bet the Gun industry will the ones to try and shut this down not anti gun people. As they are the ones that stand to lose the most. They should be looking at the music industry and prepping for the future.
Even if you have to register your printed gun. why buy one at the store if you can print out one at home from a downloaded model?
3D printing is going to change the way we think about buying and selling things all together.