The 12-gauge progressive burning smokeless powder, high velocity loads were introduced during 1922.
Early Super-X 12-ga box, Super Excellant.jpg
The progressive burning smokeless powders actually lowered pressures a bit from the heaviest loads offered with the old bulk or dense smokeless powders but moving that 1 1/4-ounce payload out at considerably higher velocity increases recoil forces which for many is an important consideration for hundred-year-old wood. The OP didn't state the frame size of his new gun. At that time most Parker Bros. 12-gauge guns were built on the 1 1/2 frame --
207492 03.jpg
but we also see 12-gauge guns of that vintage on the 2 frame --
207795 04.jpg
and less often lighter weight guns on the 1 frame --
209005 02.jpg
A while back, one of our members posted this picture of the hang-tags for 1924 vintage 12-gauge two-barrel set. The 28-inch barrels were targeted with a 1 1/8-ounce load and is stated "Use shells 2 5/8 long." The 30-inch barrels were targeted with a 1 1/4-ounce load and is stated "Use shells 2 3/4 long."
209255 01 two barrel set, 28-inch 2 5-8 inch & 30-inch 2 3-4 inch.jpg
I have saved another 1924 vintage hang-tag picture for a 7-pound 7-ounce 28-inch barrel 12-gauge and it was also targeted with a 1 1/8-ounce load and states "Use Shells 2 5/8 long."
With the North American nimrods taste for the heaviest shells he could lay his hands on I suspect that most of these old guns have digested plenty of Western Super-X, Peters High Velocity, Remington Nitro Express, etc. in their lifetimes.
Threaded Mode