FWIW -- The heaviest 12-gauge loads our North American ammunition companies offered during the time these guns were being made carried 3 1/2 drams of bulk smokeless powder or 28-grains of dense smokeless powder, such as Infallible or Ballistite, pushing 1 1/4 ounce of shot. According to some DuPont powder booklets from the 1920s and 30s the pressure of these loads exceeded SAAMI specs which came in during the mid-1920s.

[Linked Image from i.imgur.com]


[Linked Image from i.imgur.com]


[Linked Image from i.imgur.com]

Last edited by Researcher; 03/13/22 08:03 PM. Reason: change picture