From the introduction of the 28-gauge in North America it was offered in two loadings. The "standard" offering was a 2 1/2-inch shell with a load of 1 3/4-drams of bulk smokeless powder or 14-grains of dense smokeless powder such as Infallible or Ballistite pushing 5/8-ounce of shot. There was also a bit hotter load of 2-drams of bulk smokeless powder or 16-grains of dense smokeless powder such as Infallible or Ballistite put up in a 2 7/8-inch shell pushing the same 5/8-ounce of shot. From the 1915-16 Remington Arms - Union Metallic Cartridge Co. catalog --
28-gauge Bulk Smokeless Powder Loads 1915-16.jpeg
28-gauge Dense Smokeless Powder Loads 1915-16 Infallible or Ballistite.jpg
Gun cranks were doing hotter loads. In his 1910 book Chas. Askins wrote of loading 2 1/8-drams of bulk smokeless powder and 3/4 ounce of shot in the 2 7/8-inch case for use in his 30-inch barrel 6 3/4-pound Parker Bros.
Our ammunition manufacturers didn't rush to bring out a progressive burning smokeless powder, high velocity, 28-gauge load, but by late 1931 Western Cartridge Co. introduced their Super-X load with 3/4-ounce of shot in a 2 7/8-inch shell. From the April 1932
Field & Stream --
NID 28-ga Field & Stream April 1932.jpg
The first appearance of a 2 3/4-inch 28-gauge shell were Skeet Loads just before WW-II --
Xpert 28-gauge, SKEET LOAD, 2 3-4 inch 01 load flap.jpg
The 2 7/8-inch shells continued through 1948 --
Remington Express 28-gauge 2 7-8 inch New Remington Crimp 01.jpg
Super-X 28-gauge, S824, 2 7-8 inch, Super-Seal Cup Wads, Super-Seal Crimp.jpg
By the May 1949 ammo catalogs the Remington Express and Western Super-X 28-gauge loads are listed as 2 3/4-inch --
Remington Express 28-gauge 2 3-4 inch New Remington Crimp.jpg
Super-X 28-gauge, S826, 2 3-4 inch, Super-Seal Cup Wads, Super-Seal Crimp.jpg