Fortunately we have numbers to prove that ed is incorrect.
DuPont Ballistic Table that was published in Parker Brothers' “The Small Bore Shotgun” c. 1920
http://parkerguns.org/pages/PDF%20Documents/Small%20Bore%20Shotgun.pdf It is clear that this table converts Long Tons to PSI simply by multiplying by 2240; NOT using Burrard’s conversion
“All powders referred to on these pages are of the bulk nitro kind ranging from 12 (“New Schultze”, New “E.C. Improved No. 2”) to 13 1/3 (original DuPont Bulk) grains per dram…”
DuPont Bulk was introduced in
1893"New Schultze" and "E.C. Improved" in
1903Dense Smokeless powder pressures were higher. "Infallible" was introduced by Laflin & Rand in
1900![[Linked Image from photos.smugmug.com]](https://photos.smugmug.com/Shotshells-and-pressures/Pressure-data/i-HB57sQs/0/5e9a19a0/XL/DuPont%20Ballistic%20Table-XL.jpg)
Numbers require adding 10 - 14% for modern piezo transducer pressures.12 gauge
3 Dr. Eq. 1 1/8 oz. = 8,110 psi
3 1/4 Dr. Eq. 1 1/8 oz. = 8,960 psi
3 1/2 Dr. Eq. 1 1/4 oz. = 9,900 psi
16 gauge
2 3/4 Dr. Eq. 7/8 oz. = 7,035 psi
3 Dr. Eq. 1 oz. = 8,980 psi
20 gauge
2 1/2 Dr. Eq. 7/8 oz. = 12,655 psi
Very similar to modern pressures
when adding 10-14%, and the 20g far exceeds the
SAAMI recommended max. of 11,500 psiIf ed has post-WWI pressure data documenting higher pressures he is invited to post the information.
