Considering the present technology in machine shops today, they’re wanting to regulate a cat that’s already out of the bag. Once partial receivers are regulated effectively out of existence (who wants to pay transfer taxes and waiting periods on parts?) what’s to stop someone from just making receivers using a CNC machine?
And in the case of the shooter in the county north of me, neighbors had been trying to get deputies and prosecutors to do something about the guy for months. This wasn’t a surprise event to them, it was expected.
“...what’s to stop someone from just making receivers using a CNC machine?”
I just imagine it’s being done already, since some custom AR’s use CNC- billet machined lowers already, so the programming already exists and is probably being distributed.