I reload .38 HBWC's for revolver use. I am lazy and don't trim cases. I seat HBWC's about 1/16th in. proud of the typical case mouth to ensure I don't squash the occasional stretched out case. HBWC's, and all bullet types, have a considerable jump from cylinder charge hole across the forcing cone. Can't see where bullet seating depth has any effect on accuracy.