The gun design is supposedly available on the web. The fox article gives a few pictures and a video to watch. The guy only shoots one round - holds together.
The other site has more information, a forum, discussion.
Will have to look at the legality of this. Given it is made of plastic - I would have to think size - reduced - would be the goal.
Shots fired from world's first 3D-printed gun | Fox News
or go to