I think primers are the limiting factor for as long as the high demand lasts on factory ammunition lasts. All of the major manufacturers have been very candid in that they plan to only sell excess primers, if they can load them and sell ammunition as soon as it hits the shelves they will do that for as long as they can.
Up here in Alaska my good friend has seen sporadic shipments of a pretty broad powder selection hitting the shelves, as well as loaded ammo. But no primers. Shoot - we even have 6.8 western on the shelves, just no guns to use it yet!