I don't see why all the buzz about polymer
The technology to make a 1911 is over 100 years old, and quality steel is not hard to obtain.
As interesting as the 3-D printing technology is, the technology that modern metal lathes utilize is more amazing.
For some reason 3D printing has piqued the interest of computer and Internet geeks but anyone who can learn how to make parts out of polymer can make parts out of metal. Black market gun shops will open up if ever the United States flat out prohibits firearms.