Daryl,
I think I need to do that to my homemade barrel, as tight patches are a bear. the ball flattens trying to start them!
Re charges for the hawken,
I had one in percussion and used 55 gr. 2F for target, and doubled it for hunting.
It shot just as straight, but an inch or so higher at 100 yards with the double charge.
Reason for doubling, was I used the same measure, so double was easier than a lesser load.
all best,
Richard.
.590 worked with I think .018" patch lubed with deer tallow.