This document states that the pressures are
transducer BAR converted to PSI. Maybe the British are complying
https://www.scribd.com/document/97965210/CIP-Shotshell-Pressures Somewhat stunning that the Tons to PSI conversion provided to Bro. Larry by the Birmingham Proof House in 11-2001 was simply Tons x 2240 x 1.33
and not measured. I guess the Masters thought the numbers were close enough for us Colonials
2 1/2” / 3 tons = 8,938 psi
2 3/4” / 3 1/4 tons = 9,682 psi
3” / 3 1/2 tons = 10,427 psi
3” / 4 tons = 11,917 psi
Mr. Roger Hancox, Proof Master, Birmingham Proof House, 2008.
A basic “Rule of Thumb” conversion of tons to CIP transducer pressure (is) multiplying the tons per sq inch by 2240 to obtain psi, and then by a factor of 1.33 to obtain the approximate CIP pressure.