Read what Mr Curtis has to say - he is a national treasure as far as BP shooting is concerned, and then watch Mike Beliveau doing it for real with a Charleville musket of around the same era as the Brown Bess - actually, what the opposition was using in the AWoI - https://www.youtube.com/watch?v=wYu03XUbAyY

The load with wads is 100gr of FFg, period.

Enjoy!

tac