i haven't tried it in the 20s. But I have ran some of the 3" 6s in 12 gauge. We shot a whole box and couldn't get good #s. I think our best was 100 maybe 110 in the 10" at 40yds. Tried a wide range of chokes from .670 all the way down to .640 in a 870 and it seemed as if we couldn't choke it hard enough.