i have the rem 597 .17hmr[i know, i know the 597 auto is junk in most of the post] . i have shot the cci hp and hornady bt and can tell you they are both awesome out to 150 yards.i have settled on the hornady and get groups that are surprising for an auto.no jams or malfunctions after about 400 rounds.great cal. just don't hit where you want to save the meat.