3D printers can now print parts for guns. Some students recently 3D printed key parts for an AR-15 and test fired it six times before it broke. Thus, the technology exists now. It’s just a mater of refining techniques and improving alloys until 3D printing guns can be reliably done.
Thus, it no longer matters if new legislation bans 30 round clips because the clips can be 3D printed. Yes, it might be illegal to own the clips. However the point is that 3D printing increasingly will make gun control measures irrelevant. Defcad.org already has CAD files for gun parts, just download and print.