Here is something to throw into the evolutionary trail from the 1908 Sear, Roebuck & Co. catalog --
One of the links above said the .410-bore was being loaded in America by 1910. The book,
Encyclopedia of the 410 Shotshell in American 1914 - 1942, says Remington-UMC introduced factory loaded .410-bore shells in 1914. There is no mention of such shells in the 1913-14 Remington Arms-Union Metallic Cartridge Co. catalog, but they do appear in the 1915-16 Remington Arms-Union Metallic Cartridge Co. catalog --
Winchester produced their first box in July 1915. Western Cartridge Co. began production in 1916. Peters joined the fray on July 1, 1917, becoming the fourth producer of .410-bore shotshells in North America.
The last big J. Stevens Arms & Tool Co. catalog, General Catalog No. 54, circa 1914, shows this gun and says "The Gun That Introduced .410 Loaded Shells" --
