My experience with grouse is 7/8 oz loads from 20,16 or 12ga works well. I prefer 7s or 7 1/2s. Wild pheasant is a lot different. My experience there is a 1oz load will work if you restrain yourself on longer shots. But I prefer 6s for pheasants. If it is late season with much longer ranges then the 12ga with 1 1/4oz of 5s is carried.