I try to avoid 6's for pheasants, as they leave too many pellets in the meat, but I certainly would not use them on late season jumped birds.
At 30 yards there is no choke that produces as good a pattern as a full choke. The more open you go from that, the more you are handicapping yourself. (Bob Brister wrote a book about that back in the '70s.) Mod is a good compromise in case you get some 20-yard shots, but I would prefer to avoid IC for 30-yard-plus shots. You still have a hot center, but it is small compared to that of an IM or Full.
