And to further confuse us brainless Colonials, these MVs are what we would use today for the Dr. Equivalents

G.T. Teasdale-Buckell, Experts on Guns and Shooting, 1900
https://books.google.com/books?id=P7UrAAAAYAAJ&pg=PA235
1 1/8 oz. load comparisons. Pressure converted used Burrard’s formula
42 gr. = 3 Dram Bulk Nitro – 1” chamber pressure 7,985 psi / MV 1208 fps
45 1/2 gr. = 3 1/4 Dram – 9,730 psi / MV 1,274
49 gr. = 3 1/2 Dram – 11,780 psi / 1,328 fps

I still can't believe some guy at the Proof House just guessed at the Tons to PSI conversion!!

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