I will shoot just about anything at ducks, 2 3/4 up tp 3 1/2, 6 shot and up. Geese, I shoot 1 3/8 oz of BBs in 3", which is my favorite, but will soot the 1 3/8 oz 3 1/2'' if that is all that is available. Much more shot out of a 12ga 3 1/2 the pattern begins to suffer.