I realize your trip has come and gone and I hope it went well. This was our third yearly trip to SD for the conservation hunt, freelancing. This year I bought some Kent 3" shells that have a mix of BBs and 2s. The 2s are loaded first, then the BBs (the two shot sizes are not mixed) so that the BBs come out first, followed by the 2s. The patterns are tight because the 2s draft behind the BBs on the way out. I like the concept of putting out more pellets than just a straight BB shell. They worked very well on both full-sized snows and Rossies. We shot a lot of Rossies this year. I would say our max shots are 40 yards, with many closer. No 70 yard spray and prays.
I also bought a case of Kent 2s / 4s mixed in the same way. Can't wait to use them next year on ducks and honkers. I shoot many honkers with 2s because I am loaded for ducks (I don't like fumbling with / switching out shells when birds are heading in) and because we mostly shoot honkers back-winging into the spread as opposed to lower percentage pass shots.