doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Conversion tables

LB - The box is covering both bases; guns marked for 3 tons of service pressure (understood to mean that the proof load was 850 bar) and guns marked for 850 bar of proof pressure (understood to mean that the service pressure is 650 bar). We have two uses of pressure (service load and proof load), we have three measurement systems (lead crushers, copper crushers, and piezo), we have two standard systems of measure units (USA/English and SI) and two differing units (psi and tons and bar and Kg/Cm sq)within each system, differing proof laws by country, and differing proof laws by age. I think it is remarkable that we get it as clear as we do!!

If you are going to shoot 100+ year old guns, you will have to get past looking for the simplicity of simple conversions and understand what the proof markings mean.

It's clear enough to me, RM--but only because I know a bit about service pressure, proof pressure, etc. But I'm a writer and tend to be a stickler about clarity of language, and the language on that box is most definitely NOT clear as written. It gives the reader the impression that 850 bar is the service pressure of a gun marked 3 tons, which would mean that such a gun was built to accept standard SAAMI loads--which it most definitely was not.

Keep in mind, SAAMI cup, lup, & pizo, CIP lup cup & pizo, and the old British method are seven DIFFERENT ways of MEASURING the pressure and will yield seven different numbers, conversions aside. There is simply no way to directly convert from one to another, they have only a loose correlation.