my experience with ducks is #2's - #4's is your best bet and i would go with a modified choke or a full. maybe even both mod in your first barrel and full in your second. im just barely getting into doubles but i shoot 3.5 #2's at 1625fps win xpert steel full choke out of an 870 super mag and thats absolutely deadly on ducks. 1 lost cripple out of 39 this year.

i dont care who you are if you cant shoot it dosent matter steel, hevi-anything or lead your not going to hit sh**

eddie