I’m not even sure how your point differs from his. In aggregate, according to him, ghost guns are about 80% plastic; 20% metal (he didn’t comment on which specific parts were plastic or metal), he never mentioned “printing” anything, so I don’t know what you’re talking about there, and the essential problem is this: it would be illegal for a manufacturer to sell a fully assembled “non-serialized” gun like that, but it’s not illegal under state (in PA) or fed law to sell the parts. It’s not a crime until the parts are assembled. But enforcement is very difficult, because you can’t post a cop in every basement.

The cottage industry is people sell the assembled ghost guns “out of their basements”. I don’t know what in your post really refutes that, but anyway, the idea is that if selling a fully assembled ghost gun’s a crime, selling the parts that can only be used to assemble one should be too.