Some of the very earliest Eley 'Maximum' cartridges did have 1 1/4 ounce and suitable for 2 1/2" chambers although later this went down to 1 3/16ths. as they still now are. Also some very early Eley 'Alphamax' cartridges with 1 1/4 ounce were in a 2 1/2" case. These latter are quite rare and I only have one example in my collection. I would have to go back through some of my old catalogues to find the dates of change. They advertised being loaded with 'Neoflak' powder. Lagopus…..