When the 28-gauge was introduced in North America, the "standard" 28-gauge load was 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 out of a 2 1/2 inch case. A slightly hotter load of 2 drams of bulk smokeless powder or 16 grains of dense smokeless powder such as Infallible or Ballistite pushing 5/8 ounce of shot out of a 2 7/8 inch case.
28-gauge Bulk Smokeless Powder Loads 1915-16.jpeg
28-gauge Dense Smokeless Powder Loads 1915-16 Infallible or Ballistite.jpg
TARGET 28-ga.jpg
Early Long 28-gauge Peters TARGET.jpg
Around 1931-2, high velocity, progressive burning smokeless powder caught up to the 28-gauge and the 3/4 ounce load, Western Super-X, Peters High-Velocity, etc. were introduced.
28-gauge Super-X #6.jpg
28-gauge High Velocity #6.jpg
NID 28-ga Field & Stream April 1932.jpg
Shortly before WW-II, our ammunition companies began putting up their 28-gauge Skeet Loads in a 2 3/4 inch case, and shortly after the war the 2 1/2 and 2 7/8 inch cases disappeared and all 28-gauge loads came in a 2 3/4 inch case.