PAHunter,
Many years ago, when I began hunting Pa's flintlock season, I used what was then considered the standard 50 cal load--90 gr.Goex 2f with 4f in the pan. Later I began experimenting and settled on 75gr. 3f, which gave me about the same velocity in my old TC Hawken. I still use 4f in the pan in dry weather, but change to 3f (which is less hygroscopic) in the pan in wet weather. The 4f seems to fire a bit faster, but that could be my imagination. Both my old Hawken (which wears a Lyman frizzen), and my Lyman Deerstalker fire very fast with either.