British 6's are slightly larger than American 7's: 270/oz vs 299. Just shot with a collection of folks who dispatched a number of British pheasants and partridge shooting 1 oz Brit 6's. I've used the 1 1/16 oz load of Brit 6's (Kent now, Eley in the past) for American pheasants over dogs. Very effective. Also an excellent prairie grouse load, although early in the season, RST's 7/8 oz 7's out of a 20ga works fine on sharpies and chickens.