Here around the Chesapeake, market hunters tended to use the 8 ga for wing shots and larger punt guns for shooting at rafted ducks and geese. Some ran into 2 inch bores, more like cannon than shoulder arms.Common loads for the 8s were 1 1/2-2 1/4 oz of shot.
Lots of families on the Eastern Shore still have old 8 ga Parkers,LC Smiths,Ithacas,etc, oft in rough shape as heirlooms and wall hangers. Waterfowling guns, especially during black powder days, took a beating internally and externally.