When the Super-X cartriges first came out circa 1922, the 3-inch 12-gauge Super-X contained 1 3/8 ounces of shot. Around 1935, when Winchester/Western brought out their Model 12 chambered for the 3-inch 12-gauge shell, they upped the payload to 1 5/8 ounces and called it the 3-inch Magnum. Nash Buckingham always seemed to favor the original 1 3/8 ounce load, though he did jump on the circa 1928 introduced Lubaloy shot.