The 2 7/8 inch length for the 10-gauge shell was the North American "standard" from at least the 1890s. The heaviest factory smokeless powder loads offered in the 2 7/8 inch 10-gauge shell were 4 1/4 Drams of bulk smokeless powder and 1 1/4 ounces of shot, or 34 grains of dense smokeless powder such as Infallible or Ballistite and 1 1/4 ounces of shot.
I think it was in late 1925 or 6 when Western Cartridge Co. applied their progressive burning powder work to the 2 7/8 inch 10-gauge shell and brought out their 1 5/8 ounce Super-X load, often referred to as the Super-Ten. The first Western Cartridge Co. paper I have that lists it is dated Jan. 1, 1927. By their 1927 catalogue Peters Cartridge Co. was also offering the 1 5/8 ounce 10-gauge load in their High Velocity line --
