A home 3D printer is a careful machine, but also a dumb one. It can't tell the difference between a firearm and a firehose. It reads a list of movements, heats a nozzle, and lays down plastic or metal in thin layers until a shape appears. That list can describe a bracket for a shelf, a replacement knob for a dishwasher, or a receiver for a firearm. To the printer, those files are the same kind of thing: geometry.[1]
On 26 September 2026, California Governor Gavin Newsom signed Assembly Bill
