I have 2 870's one supermag 3.5" one 3" SPST. I shoot Briley .665 straight rifle choke on both 100% awesome. I just got a SX3 NWTF and bought same briley choke for it. I haven't patterned it yet but will use supreme 3.5" and 3" Winchester Supreme (black shells). I also have a box of Winchester long beard #5 to try. I have used Winchester Supreme #5's since 1994 they are great with these chokes. .660 to .670 for lead #5 shot