It's been several years since I hunted birds, but with my Beretta I used to like using the improved cylinder tube in the bottom barrel, and the full choke in the top. When hunting pheasants often they would be running with the dog in pursuit, and it might be 50 yards or more when it flushed, so I'd switch to the top barrel and take it with the full choke, and usually a 1 1/4 ounce load of 5's. But many times they would hold tight and I'd have a 15 yard shot, which I would take with the bottom barrel and usually a 1 1/8 ounce load of 6's. If it was later in the season I might have the heavier loads in both barrels.