I'm not exactly a pro, but if anybody has better advice or something to add, please chime in. Every gun is different. You'll need to check different loads and if possible, different chokes for your gun. Different extra full turkey chokes will pattern differently in the same gun, as will different shot sizes. Try shot sizes 4, 5, and 6 from different manufacturers and see what patterns best out of your gun out to about 35-40 yards (range may be a little less since you are only shooting 2 3/4" shells). You'll want the most dense pattern you can get.