Back to the original .410-bore thrust of this thread! I just opened my box of goodies from the latest Wards auction and included was a 1925 J. Stevens Arms Co. catalogue No. 56 and in doubles both their No. 330 Stevens Hammerless and the cheaper No. 315 "Riverside Arms Co." Hammerless are offered in .410-gauge.

Also, I more then doubled my collection of various iterations of Western Cartridge Co.'s booklets Super-X The Long Range Load by Capt. Chas. Askins. By the 1924 version they are including the Super-X 2 1/2 inch .410-bore shell.