At the time your gun was built, the "standard" 20-gauge shell in North America was a 2 1/2 inch case carrying a maximum charge of 2 1/4 drams of bulk smokeless powder or 18 grains of dense smokeless powder such as Infallible or Ballistite pushing a 7/8 ounce payload, and lighter loads of 2 drams or 16-grains and 3/4 ounce were common. In the extra cost, extra length shells of 2 3/4, 2 7/8, and 3-inch one could get 2 1/2 drams of bulk smokeless powder or 20-grains of Ballistite or Infallible pushing that 7/8 ounce of shot a bit faster.
The high velocity progressive burning powder 1 ounce 20-gauge loads were introduced by Western Cartridge Co. as their Super-X in 1922 in their 2 3/4 inch FIELD shell.
Hybrid Mode