Got a chance to try out my 870 20ga (21" barrel) today shooting 3" magblends and a hevi-13 choke. The range was 35yd. and I feel pretty good about this setup. I think the load hit a little to the right due to the high winds we are having today in NC. They were blowing 18-25mph from left to right. I would love to try out some of the Federal Heavyweight or some TSS #9 out of this choke if someone would like to send me some