I think I've got data, just have to dig it up. Might be a few days.
I load the .41 Long Colt, but use heeled bullets instead of the HB's. I heard somewhere that when using the HB's with smokeless, you need a fast powder to get proper bump-up of the base. Red Dot was recommended (I think). I never had good results with HB's in the .41, and was lucky enough to find two old Lyman molds for the original heeled bullets.