“There will need to be a grass roots ammo mfg infrastructure.”
I remember in the Philippines and Vietnam when in the service and I know that here and there in the U.S., if there is a need, a supply will surface. Call it a black market, call it smuggling, call it what you will, the need will be met if the money is there.
With enough garages pounding out brass, pouring lead and doing assembly, we can get through this.