well, in mythinking, and im probably wrong, i have always thought a 3 inch 20 gauge shell would be equivalent to a 2 3/4" 12 gauge shell at the most, it may not even be equivalent to that, and i like having as much of an advantage as possible on these birds, to a certain extent, i use 3" winchester super x #4's #2's for ducks and geese, but me goose only load is the 3" dryloks that are bbb