doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com 2 3/4 inch to reduce pressure or not

Many of our vintage double gun manufacturers followed a policy of holding their chambers 1/8-inch shorter than the intended shell -- in 12-gauge 2 5/8-inch chamber for the 2 3/4-inch shell, in 16-gauge 2 7/16-inch chamber for the 2 9/16-inch shell and in 20-gauge 2 3/8-inch chamber for the 2 1/2-inch shell. Parker Bros. and A.H. Fox Gun Co. for sure followed this policy. The Remington specification sheets for their Parker doubles were reproduced in the two-volume book The Parker Story show this. Here is one of the pages --



What may have been done to a chamber in the 100 +/- years since a given gun was made is impossible to know. I for one, can't see any benefit of removing metal from a critical area of a shotgun barrel.

The heaviest 12-gauge loads our North American ammunition manufacturers offered back in the day in 2 3/4-inch or longer shells were 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. These loads were actually a bit higher pressure than our current SAAMI specs for 2 3/4-inch 12-gauges.







After the Great War our ammunition manufacturers went to work applying the progressive burning smokeless powders developed during the war to shotgun shells. First on the market was the Western Cartridge Co.'s Super-X in 1922 with Peters High Velocity and Remington's Heavy Duck Load (soon morphing into the Nitro Express and later Remington Express) following quickly. These progressive burning powders moved out that 1 1/4-ounces of shot at higher velocity but actually lower pressures than the old bulk or dense smokeless powders. That 1 1/4-ounce of shot at higher velocity meant greater recoil forces being applied to the head of the stock. That wood is now 60 years older than when I started playing in this vintage doubles game.