Like already said, the only way to get that powder to ignite in a flintlock is to duplex it with some real black powder. Even 20 grains of black powder first and then the Pyrodex P. Of all the powders out there, Pyrodex is one of the hardest to ignite. I think you'd be in for a very frustrating and disappointing day with just Pyrodex P.

Since you have to order powder, get one pound (one can) of 4f. 3f will do the same for you, but 4f flows better out of the small pan powder flasks. Some rifles like 3f, some 2f for the main charge. So I would also get a pound of each of them. BUT you start shooting a lot with that flintlock, and a pound of powder disappears fast. A couple long range days, and I can burn off a pound of powder. So you might want to stock pile since it is not there, in your area. I personally get ten pounds of each when I buy powder. 10 of the 2f and 3f. One pound of 4f will last you a VERY LONG TIME. I been shooting these things a number of years and finally burned off a pound of 4f powder. I always figured a pound of that give you about 1500+ prime charges.. so that is a lot of shooting.

For powder, I like Goex, Graf's & Sons, or Swiss. Swiss is a great powder, but it is costly. Goex and Graf's do the same job and work excellent. Graf's & Sons sell their powder (made by Wano of Germany) of less then Goex.. And there is a $25.00 hazmat fee to mail it.