As the North American .410-bore shell grew from the European 12mm, the original 2-inch shell contained 3/10 ounce of shot. When the 2 1/2 inch .410-bore shell was introduced it contained a whopping 3/8 ounce of shot. About the same time Winchester/Western introduced the 3-inch .410-bore shell with 3/4 ounce of shot, the payload of the 2 1/2 inch shell was upped to 1/2 ounce of shot.
I've found that more often then not, the Stoeger Catalogues lag by a year or so what appears in the actual manufacturers catalogues.
