Sorry this model is out of print
It looks as though printing a fully functional gun is very likely rather than unlikely, fortunately the technology should be out of the reach of most disgruntled High School kids with a clock tower to climb.
What is more interesting is how far forward the expectations have moved in the few years that 3D printers have been going. I can see the technology developing even faster now for military/aerospace items and also the possibility for specialised parts where laminations and hardness and temper can be applied differentially as the part is being printed. Almost like printing a katana.