I agree with Ranger on all but one point.
Old wives tale, or Black Powder voo doo, says one grain per caliber number as a starting load, and two grains per caliber number as a maximum load. This has proven to be fairly reliable over my 32 years experience with black powder rifles. Whether patched round ball, or conical bullet best compromise between accuracy and power will be found in that range. (This is valid for the 45 to 54 cal rifles, so 44 cal should also fit in here) By this saying 88 grains would be max, 44 would be starting. Split the difference and you get 66 grains. My money is on a load of 65 grains of 2F Goex being best.