marvin martian
Diamond Member
Interstate commerce is governed by Federal Law not state.
Here's how California banned online ammo purchases from out of state (or in state):
(b) Commencing January 1, 2018, the sale, delivery, or transfer of ownership of ammunition by any party may only occur in a face-to-face transaction with the seller, deliverer, or transferor, provided, however, that ammunition may be purchased or acquired over the Internet or through other means of remote ordering if a licensed ammunition vendor initially receives the ammunition and processes the transaction in compliance with this section and Article 3 (commencing with Section 30342) of Chapter 1 of Division 10 of Title 4 of this part.