I used Eley VIP 21 gram (3/4 ounce) number 7 shot for pheasants last season and was most impressed. Going to give them a further trial this season too. One ounce loads may suffer pellet deformation in such a small bore a bit like the 3 inch .410. All I can say is try them and see but a sub 6 pound gun will be unpleasant to shoot. Lagopus.....