Great to see all the interest in 2" guns. Getting a pheasant with one is, indeed, a fine achievement.
Years ago there was an older member at my gun club who introduced me to the 2" shell. He had a significant supply of these shells that he used to reduce recoil in his traditional 2 3/4" gun. He gave me a few boxes and they worked surprisingly well---think the payload was 3/4 or 7/8 oz .