Late season shots are "generally" longer on birds that have been hunted for a couple months. In addition, the birds are heavily feathered by late season in the northern pheasant belt. That all being said, I use the same ammo all season, mostly because its scarce and I don't have the luxury to pick and choose like the good old days. So my load from beginning to end of season is 4s or ideally 5s if I can find them. I also don't mess around with anything over 2-3/4" in my 12s. I shoot 3"ers in my 20.
