Mentioned in C. John Sullivan, Jr's books the gentlemen shooting on the bar at the Carroll's Island Ducking Club were using 11 to 12 drams of black powder and 3 1/2 ounces of shot in their big 4-gauge guns. From what I've found in old ammunition catalogs only Union Metallic Cartridge Co. and Winchester offered 4-gauge NPEs. Peters and Western didn't bother with this very limited market. From what I've found the big ammunition companies didn't provide loaded 4-gauge shells. They were either loaded by the users or local loaders.
UMC 1887 --
4-gauge 1887 brass.png
4-gauge 1887 paper.png
UMC 1901 --
4-gauge, 1901.png