[LorenPechtel]

It's California. Not the first time they've gone bonkers with firearms dreams. (Microstamping--the firing pin is a wear item! Biometric--ever see a system that's fast enough authenticating the user?)

There is exactly one use case for a home 3D printed gun: get it past a metal detector. It's bulky, inaccurate, fires only once and even then with some risk to the person firing it. And I can't imagine a filter that could remotely reliably distinguish "gun" if an effort is made to disguise the parts.

The actual ghost gun issue is with CNC milling machines, not 3D printing. It used to be that while building a zip gun wasn't a big deal but building anything resembling a modern semiauto (or even full auto) firearm was in the skilled machinist realm. Now CNC machines can bring this down to merely requiring someone who knows their way around tools--which comprises an awful lot of people.

Unfortunately, the politicians routinely treat these two radically different things as if they are one.