The heavier the payload, the harder it is to drive it fast enough to be effective in smallbores. I have shot a lot of Dove in late season, with both 3/4 ounce and 7/8 ounce loads. I find the 3/4 ounce gives better results. I do drop down to 7 shot. I'd rather use 3/4 ounce, 7 shot driven at 1200-1250 fps than 7/8 ounce of shot driven at 1150fps. I do not like the 1300 fps loads. Too fast and it does not pattern well and too slow does not retain enough energy. Pick your poison. Longshot or 572 are excellent powders to start with.
It is all about tradeoffs. 1150, 1200, 1250 or 1300fps, 7/8 or 3/4 at a faster speed. Which patterns better? Which shot retains enough energy down range. As a young person I killed several hundred Ducks with a 28 shooting 1 ounce lead number 6 or 5 shot under very favorable conditions. Longest shot was 25 yards. I have killed several hundred late season dove with 3/4 ounce 7 shot. That does not give you many pellets, but the retain energy does kill birds in a modified or full choke gun. Load a few and pattern them to see what you have. The small gauges need the best components you can find because they have little margin of error and tend to unforgiving.
