In the years after The Great War, our powder manufacturers were working on applying things they learned during the war to shot shells finally resulting in progressive burning smokeless powder, high velocity, loads coming to the market in 1922. During this time DuPont made No. 93, DuPont DeLuxe and finally settled on DuPont Oval.
From Winchester Catalog No. 83, 1925, what you have there are two shells of Load No. 43, 28-grains of Infallible pushing 1 1/8 ounce of shot and one Load No. 44, 3 1/2 drams (equiv.) of DuPont Oval pushing 1 1/4 ounce of shot.
LEADER Loads Catalog No. 83, 1925 Load No. 43 and No. 44 underlined.jpg
LEADER 12-gauge 2 3-4 inch OVAL Load No. 44O6C.jpg