My uncle works in a machinery factory. The high-grade lathes they have have GPS-trackers built in, and moving them any signifigant distance, even just out-of-state, will get the military on their ass. Of course, these are the kind of lathes that could build more than a simple gun-triggered warhead. They could carve out the necessary solids for a levitated-pit implosion warhead, or possibly even the framework for a fission-fusion-fission thermonuclear device.
Have you got any way at all to confirm this, apart from what your uncle told you? edit: google hasn't given me any information on this at all. I'm still calling shenanigans.
I'm just not seeing how those would be any different than a 5 axis CNC machine, and those aren't GPS tracked from what i know. Maybe i'm just underestimating the sort of accuracy that a nuclear weapon requires, or something.
Someone successfully built an AR-15, or at least the receiver (the part that is considered to be the gun for legal purposes because it is where the serial number is printed, you can buy the other parts without regulation) on a printer and found it to be fully functional with more than 100 5.56 rounds through it. I'm sure I'm off on some facts, here's the original article I read.
Ninja edit: ...only parts printed were the stocks. (to be precise, the lower receiver).
No! Bad! How do you equate "lower receiver" with "stock"? It is the most important part of an AR-15 because it is the only part which is legally regulated.
It may be the part which is regulated (which is silly, if you ask me, for the very reason of that 3d printing), but really, it isn't the most important or complex part of the gun
mechanically. It is just a shell to hold components in place.
edit: however, you are saying that you can buy trigger assemblies, barrels, upper receivers, etc without any regulation? in that case i can see how the ability for anyone to create a lower receiver is a huge issue, and is "creating a gun" in a legal sense. It still isn't creating a gun in a practical sense though.