My understanding is the 9mm doesn't group as well as 357/38 due to case/bullet length and smaller diameter of the 9mm. What size groups are you getting from the 9mm compared to the .38 at 25 yards? I realize this will vary with the revolver, the shooter and good days v bad days. I just kill paper, metal targets and tin cans. But only "accurate guns are interesting" and there is no point to me in paying for the 9mm cylinder if it doesn't group decently.