Chris, hard to say which powder is the best, people develop personal preferences. If you can get "Nice Shot" the published load using 33gr of Longshot with 1 3/8 ounce is a good one. Frank Cronin uses it all the time.

There are few situations where I would feel under gunned on waterfowl with a 1 3/8 load of bismuth in a short ten.

You may have to step into the land of looking at all the reloading data on the short ten spreadsheet and making some deductions and shoot some wildcat loads. I have used SR7625 for bismuth myself. For instance I took that 1 1/4 ounce bismuth load I referenced in the Rem hull , I used a roll crimp (instead of the 6 point) and loaded 1 3/8 ounce. Not published but works great.

Thanks Pete !