Actual Laws aside, I get goosebumps thinking that this isn't completely sci-fi. Just because you can't print the whole weapon now doesn't mean you can't do it in 15 years or so. I can't wait till home depot is selling you "models" of nuts and bolts rather than actual nuts and bolts!
It is actually quite possible to print the entire gun, if you wanted to use a metal Selective Laser Sintering machine. They are just cost prohibitive ($500,000+).
