First, almost anyone who would use this to manufacture gun parts knows guns and what parts they want to make, and can create the parts they want by themselves, given enough effort and skill. They cannot ban the transfer of knowledge.
Second, passing a law against possession or manufacturing is unenforceable. Homeland Security can search your house as often as they want, but will only find a printer and spools of plastic filament. The parts won't exist until the person wants them to exist, and whether it is to shoot school children or fight tyranny, the police won't know when the person pushes the print button.
Third, lawmakers want to ban specific items like gun magazines that will fit into certain models of commercial manufactured weapons. But the real genius of the additive manufacturing wave is to push down to the masses a technology that allows them to create personalized objects of their own design. A skilled craftsman can use tools to create new weapons, not just copies of commercial manufactured weapons, that cannot be foreseen by legislators or law enforcement. They may not be even be recognizable as weapons until they are used. Legislators have no ability to ban things that can be made individually and can't be predicted.
We are not crossing into a dangerous new territory, it crosses into an old territory when the local blacksmith had the power and knowledge and tools to create weapons by himself. And yet we survived that era fine. We need to concentrate on the character and mental state of the people involved more than the technology.
Points well-taken.
Your point #3 reminds me of the proliferation of “designer drugs” being mfg’d by simply changing a chemical formula, in someone’s garage lab, thereby getting around the DEA/FDA laws and causing them to scramble to pass new regs/laws.
Run, rabbit run!
Soon, you'll need an Android cellphone to use as your base, and some cheap plastic pipe to stuff small rockets with miniature guidance systems into ~
Those early armories looked a lot like livery stables with resident ironsmiths. The future armories will look a lot like a kid on a cellphone with plumbing parts.
Pashtun tribesmen in the tribal areas of Afghanistan apparently make pretty good AK clones. What people don't seem to understand about the gun is that it's a 19th century technology, and most of the changes made to it since then have been design changes rather than to the basic process of making one.
This was one of the best posts on FR in a long time. Well written, with a fundamental understanding of the topic. Kudos.