Wickard v Filburn.
Raich : Terminally ill elderly woman grew pot for own medical use under doctor's supervision as allowed by CA law; was deemed subject to regulation* thereof as reducing demand in an illegal interstate market.
Stewart : Convicted felon makes homemade machinegun, impossible to legally move in interstate commerce (can neither buy nor sell); was deemed subject to regulation* per Raich verdict.
Ergo, the commerce clause is moot. These states may declare portions of their intra-state arms market not subject to federal regulation, but Wickard established the "fungible" principle despite obvious non-interstate use, Raich applied it despite state legality, and Stewart applied it to firearms. These states are trying to forge a path in already-paved territory.
(* - to wit: prohibition)