ya know im no professional, but id say that more shot would be better.

Ok I don't know if you ever hunted water fowl with lead, but back in the day we killed alot of ducks deaad with1 1/8 oz6s and geese with 4s. Steel is 2/3 the wieght of lead , for pellet count thus pattern density, 1 oz of steel is the same as 1 1/4 of lead and an 1 1/8 oz steel is like 1 1/2oz .
I've killed honkers with 1oz of steel b's at 1500dead at 40 yds . hand loads with little recoil in a 2 3/4 case , of course I also had all 117 pellets inside the 30 inch circle at 40 yds . I would say speed over payload. I also dont care for rem nitro mags . Pmc sells some inexpensive loads that are pretty good untill it gets under 30 degrees , they were about 5.00 a box .

Just use Federal T Shot. i use ut for snow geese and i shoot a lot higher than tree level,trust me they will work.