The "ballpark conversion figure"--which I don't think works for the much higher pressure crusher-measured rifle loads (CUP rather than LUP)--is LUP + 1,000 = psi.
Even after the Brits dropped the tons proofmarks on their guns and started using bars (mid to late 80's) they were still using crusher rather than transducer values. For example, circa 2000, I got the following number from the Birmingham Proofhouse: Standard proof (850 bar proof marked on the gun; 650 bar service pressure) converts to 13,920 psi proof pressure and 10,730 service pressure. You can't get there via the 14.5 x bar = psi formula.
Last edited by L. Brown; 07/19/17 10:37 AM.