Personally, I shoot an IC to LM choke with #3 3" 1 3/8 oz high velocity Kent Fasteel at ducks and go to 3 1/2" BBs on geese and open the choke to the IC. I' m shooting a Beretta Xtrema.

In my O/U, I shoot Colonial' s IC and M steel-shot extended tubes loaded w/the same duck load I listed above.