I could ask LLM to find me "legal" parts that are 1:1 with gun parts or even better find metal parts in craftcloud3d.com or sendcutsend.com. With big enough database it could find right items on Amazon. It's impossible to legislate.

true but the government will inevitably demand their own stanza of (blocking) system prompts in the major AI services. then they will ban local LLM and foreign ones.