After some fairly extensive pattern testing and a lot of waterfowl hunting, I choose to shoot my Remington 12 ga. with the Mod choke and #1 steel. Best thing to do is to pattern your gun with Mod and IC with each pellet size. Full is most likely too tight and will probably "blow" patterns causing random holes at the edge of the pattern and too much center density. Shoot at a large sheet of paper from your typical distance - most choose 40 yds, but there's nothing magical about that. 30 yds is typical shooting distance over decoys. A killing shot delivers at least three pellets in the body of a bird, and no bird sized holes in the pattern. Shoot at least three shots for each combination of choke shot size and distance. Even if you can get good long distance patterns, power drops off quickly with steel, and I think you'll soon find out that about 45 yds is max. for most steel loads. But, best to decide for yourself.