The two guns with these "
FOR STANDARD VELOCITY ONLY" markings that I know the serial numbers for both date to 1929.
When Western Cartridge Co. added the 16-gauge to their progressive burning smokeless powder, high velocity, Super-X loads, they put it in the 2 9/16-inch FIELD shell. The first mention of the 16-gauge Super-X that I've found appears in a Western ad in the October 1922,
National Sportsman.
While Remington and Peters followed Western's lead and put their 20-gauge progressive burning smokeless powder, high velocity, loads in 2 3/4-inch shells, Winchester, with a load of 2 1/2-inch chambered Model 12s in shooters hands, put their 20-gauge progressive burning smokeless powder, high velocity, loads up in both 2 1/2- and 2 3/4-inch cases.
Super-Speed 20-gauge, 2 1-2-inch, #7 1-2 Ch. Shot.jpg
Super-Speed 20-gauge, 2 3-4-inch, #6 Shot.jpg
LEADER 20-gauge, 2 1-2 inch, Oval, 1 ounce.jpg