I know this is an old topic, but I have to agree with Swamp Pup, DuckHtr. A thirty-yard shot is a long shot for me. 2 3/4in #2s is about all I use, it nocks them Butt-end over apple cart. I do use 3in #2s in late season depending on the day and the wind.
I have this guy at work, which kept telling me "I needed a 3 1/2in," and "I wood be smart to buy 10ga." I thought to my self I've got see this guy in action, so I took him on a night-hunt. I can't begin to tell you how impressed I was; he brought his 10ga, he was shooting reloaded Ts. To make a long story short he missed every duck, and goose, he shoot at. Oh he did hit the one that landed in my decoys. That drake Mallard was 20yrds away; it took two shots to kill it, with 10ga Ts I thought, "I would be smart" not to take this Ya hoo again. And I haven't.
I don't know, I guess I'm old school, don't get me wrong. More power [ no pun intended ] to the guys who have them, but I don't see the need for all that fire power. Over the years I've killed a lot geese and ducks with my 2 ¾ and 3in #2s. Besides I want them so close I can see them say to them selves OH SH$$