Good memory. It was "The Southern" chamber burst.
A sample of Cheddite for Herters “Select Field Dove and Quail” 1 oz. at 1165 fps, or the old 2 1/2 Dr. Eq. showed pressure averaging 12,500 psi with one at 13,400 psi.
Another Herters sample was measured by Tom Armbrust at 1,200 fps and 11,500 psi.

For historical comparison, DuPont Brandywine Experimental Station data cited by Charles Askins in 1933, with DuPont Bulk Smokeless Powder
16g 2 3/4 Dr. Eq. 1 oz. - 4.54 tons X 2240 = 10,170 psi plus 10 - 14%

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