Are you familiar with Defense Distributed, DEFCAD, and the Ghost Gunner? That stuff is already here. Every time I hear someone talk about banning "high capacity magazines" I think how trivial something like that is to 3d print...
I've heard about them a little. This stuff is definitely getting easier, but there's still a world of difference between the difficulty of replicating a gun and the difficulty of replicating a copy of crypto code.