Invest in some guns that are chambered in straight-wall cartridges. .357's, .44 Rem. Mag, .45-70, .45 LC etc...
You can use black powder and black powder substitutes to load those, as well as smokeless. A .454 Casull with a full case of Pyrodex is nothing to sneeze at either and in case there is a shortage of the regular powder or ammo that you use, you can break out the old smokers and still fill your dinner table and protect your home with ease and confidence.
Good advice, along with enjoying muzzleloaders. They never were my thing until semi-recently. I enjoy my smokepoles as much as my other firearms now. One day I will experiment with making that holy black. That plus casting (so long as I have enough lead on hand) will ensure that I can continue to shoot should there be long term shortages of components. The only thing to stockpile would be primers/caps