From my years of observation, it appears to me that Remington ARROW shells are far and away the most common North American 8-gauge shells we see.
The last Remington catalog I've found to offer loaded 8-gauge shells is the 1918-19 The Remington Arms Union Metallic Cartridge Co. Inc. catalog. The 1923 Remington Arms Co., Inc. catalog still offers 8-gauge NPEs. However, the bulk of the 8-gauge ammo I see offered in sporting collectibles auctions is Remington Arms Co., Inc. which would make it from late 1920 onwards, some even after 1934 with the DuPont logo on the labels --
ARROW 8-gauge, 5 1-2 dram equiv., 1 3-4 ounce #2 C DuPont.jpg
ARROW 8-gauge, 5 1-4 dram equiv., 1 3-4 ounce #4C DuPont.jpg