I suppose this is a question for Dr Drew. For years I have been told that 22-23 grains of 7625 with a WW209 primer and WW12AA wad with 1 1/8 oz shot equaled about 5600 PSI. The Lyman book shows 7200-8400 LUP. I have an 1889 Remington Hammer gun that has had 5000 to 7500 rounds of this load put thru it.
Dr Drew do you or anyone else have any info on this load?