Vintage Shell Pressures

[Drew Hause]

Not sure how I've missed this DuPont Ballistic Table all this time but this should settle some questions; from Parker Brothers “The Small Bore Shotgun” p. 12
http://parkerguns.org/pages/PDF%20Do...%20Shotgun.pdf
p. 7
“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…”
Original “E.C.” and “Schultze” were 14 grains/dram

First published c. 1915 but this appears to be an after 1920 edition
Forest & Stream
https://books.google.com/books?id=lR...J&pg=PA247&lpg

Frank and I were discussing this on another thread, but I couldn't find it.

It is clear that this table converts Long Tons to PSI simply by multiplying by 2240; NOT using Burrard’s conversion.

Compare the 3 Dr. 1 1/4 oz. DuPont Bulk pressure of about 9,600 psi in this 1933 pressure-curve from "Smokeless Shotgun Powders: Their Development, Composition and Ballistic Characteristics" by Wallace H Coxe; E.I. du Pont de Nemours & Co.



The powder appears to be a 36 grain = 3 Dr. Eq. Bulk



These 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 (that is significantly higher than other reported Bulk and even Dense pressures)

"E.C." and "Schultze" Bulk both ran slightly higher than DuPont Bulk

DENSE Smokeless Powder pressures would be 1000 - 1,500 psi higher

Lots more numbers here
https://docs.google.com/document/d/1...UOZEFU/preview