I used to shoot 70 gr Swiss 3F in my 50 flinter. Made life easy, 1 can of powder, 1 box of balls, 1 bag of patches, 100 shots. Flints, around 5 over the coarse of that much shooting.

I currently use 90 grains of 2F under a 295 gr T-EZ, which I think is on the light side.