I go with Coondog!
I've been using 90grn of fffg in a T/C 50 cal Hawkin for
better than 25 yrs! That gun still fires every time and is flat out dead on at 100yrds! The max I believe is 100 of ffg so I figure
I'm just about the same! I feel I get better ignition w/o any
hang fires by using the finer stuff.