I'm really interested to see how all this is going to play out with all the states rights issues, between the DEA and the 12 or so states legalizing medical marijuana, the ATF and Montana, Tennessee, and soon to be Alaska, Texas and Florida fighting for the firearms.
It already played out. Go read Gonzales v Raich.
State legal Marijuana was being grown for personal use, never intended to be sold or enter even state level commerce, nevermind interstate commerce. It was considered still subject to the powers of the federal government by the SCOTUS because it would still effect demand. They also said there would be such a strong black market demand it could still end up in commerce.
Both arguments could be applied to firearms the same way.
Then Scalia, not happy with only that logic, which already covers 99% of things, added additional logic to take it even further stating that anything considered "necessary and proper" even if it has nothing directly to do with commerce is under federal jurisdiction.
As of Gonzales v Raich there is no state's rights on federally regulated items. Including firearms.
This was demonstrated matter of factly in United States v Stewart, which while not officially a SCOTUS decision, was in fact a SCOTUS decision.
In Stewart the 9th Circuit found that a homemade firearm never intended to enter commerce, be sold, or cross state lines, was not part of commerce. That because federal jurisdiction is only through regulation of interstate commerce powers, the NFA did not apply to such firearms.
Then it was appealed to the SCOTUS. The SCOTUS having just previously ruled on Raich sent the case back to the 9th circuit, telling them that "in light of Raich" they had to come up with a different outcome. They did, reversing thier previous decision, and deciding it was in fact under Federal Jurisdiction. They reversed it because the SCOTUS told them to reverse it, so it should leave no doubt in your mind what the outcome would be in the SCOTUS.
All firearms under Gonzales v Raich are subject to federal jurisdiction, and federal laws and regulations apply, as decided by the SCOTUS.