It appears that Grafs had stock earlier today but it's gone now. Regardless, Hodgdon has said they have no plans to cut back on Triple 7 or Pyrodex, so you should still be able to shoot your revolvers and rifles. Not sure about Triple 7, but Pyrodex can be used in rifles, pistols and revolvers .50 cal and under (Pyrodex P), and rifles, pistols and revolvers .50 and up (Pyrodex RS) as well as black powder cartridge. Also, Hodgdon says RS can be used in flintlocks by first pouring 5-10gr of black powder down the barrel as a "kicker charge" and topping off with P or RS after reducing the main charge by the number of grains of black used as the kicker. Example; if you normally load 85 grains, use 10gr black powder as the kicker charge and 75gr of Pyrodex as the main charge. Of course, you will have to use BP for the kicker and in the pan. This should help conserve BP if you can't get any for a while.
Personally, I believe Swiss and Schuetzen will step up to fill the gap and all the hoarding going on right now will pass.