It won’t come to that. They’re not THAT stupid.
Instead, they’ll pursue a dual strategy of “starvation” and “death by a thousand cuts”.
The Obama can order the BATFE to slow, stall, or stop its facilitation of the arms business. Increase inspections, slow paperwork processing, or just flat out refuse to approve anything needing their approval. NICS stops, FFLs fold up, imports halt ... you can buy whatever you want, but nobody can sell to you retail. Glock, Sig, FN, Wolf, etc - no more imports. I’ve already seen waiting periods take down good stores because the customer base dried up; imagine all “instant” checks failing to process, everyone having to wait 3-5 days. Consider every mandated FFL renewal going unprocessed; businesses expire for lack of one paper.
Sure, you can keep what you have, but no resupply of consumables (ammo), no repairs, nothing new. Private sales still legal, but prices increase 10-100x (see the legal machine gun market).
No door-to-door confiscations, but huge increase in hassling. Federal agencies directed, and other jurisdictions encouraged, to assume all guns contraband until proven otherwise. NY and other states start their gun laws with “all firearms are illegal” then list exemptions; as LEOs are not expected to understand the nuance of laws, just throw anyone found with a gun into a cage and let the courts sort it out.
And of the courts, the Obama just lets cases pile on. Long delays, high costs, frequent rulings in his favor, years before the core problems percolate up to an already-bought Supreme Court.
Thanks, Congress, for handing the 2nd Amendment to a hostile Executive Branch.
The real issue, as you noted, is the FFL problem and interstate shipment of ammo and firearms.
I think the only legal solution to that issue is having the states start creating a semi-organized militia-- if you have the equivalent of CCW training, you can get what you want from a state armorer.
The state buys the firearms and sells them to you as a militia member, possibly using existing FFL holders as the base of armorers.
Of course, when the BATFE swoops in they'll have to be stopped by state or local law enforcement. Or the local militia.