Ruskin,
I haven’t seen anything on boolit weight, or maybe I missed that…
I shoot H-110 in my 357 Magnum, 44 Magnum, and 45LC and I don’t seem to have the “powder in the face” problem…
I am using “heavier than accepted” boolits for each cartridge. That may help get the powder all burnt…
I do apply a crimp, but not the “heavy” crimp as often mentioned…
I always use a magnum primer…
I am a bit puzzled about powder coming back at you. Are you sure it is unburnt powder? Even a misaligned cylinder to bore I wouldn’t think would throw debris back your way…
Good-luck…BCB