westrayer
40 Cal
Your 60 grains of FFFg is still pretty light for a .50 cal. I run 80 in my rifles with patched ball. Although I really don't think I need to shoot a flintlock out to 100 yards, I do all of my shooting there when looking for best groups (in any gun). Your best group at 100 will be your best group at 50 yards. I have had a couple of times where 50-yard groups seemed fine but fell apart at 100.