My findings prove none. In fact 2 3/4 do dam near as much as 3 inchers and 3.5 incher seem to pattern like [bleep]. Sky bustin water foul or long shots at turkeys are not my gig. I would rather work em, see them decoy, and shoot em close up and personal.
The guys i see shoot 3.5 inch ammo dont know what a good pattern is much less ever pattern there own gun. I really wanted a 3.5 inch gun when thay first came out and bought 3 looking for just 1 to pattern worth a dam and none did, at least not better than a 3 inch gun at given distances.
YMMV
