I use a improived to help manage my shots to be within 40 yards. I really hunt the early season and late December - January for ducks and geese, but when I do, I use Bismuth # 4 or 5 2 3/4 inch loads even though my gun can take a 3", and the Bismuth will clean them out of the air like nothing else. The chant is whe they get close,m give them the Bismuth.
I think the ammo selection is more important than the chokeas long as you don't pass shoot at 50 yards. Let 'em get close, then let them get closer, when you can see their eyes and hear their beaks clacking, shoot them and they are in range. Mark a 40 yard spot when you set your dekes and this will help you from shooting too early. You rarely hear a hunter say he shot too late...
Feeshon [grin]