Brother Larry,
Is my service pressure to low for 850bar proof? Do I have my numbers wrong? I always thought 850proof was 650service.
Is 650 service 10730psi transducer not 9427psi?
I sure don't want to be spouting bad info!!!!
You and Rev Drew are the guys when it comes to pressures.
Best,
Bill
Bill--Your proof pressure figure for 850 bar, converted to psi, is correct. And 650 bar is the service pressure. But those are both figures derived from lead crushers. They need to be converted to transducer pressures, at which point you can multiply x 14.5 to get the results. 850 bar proof and 650 bar service are actually 960 bar and 740 bar, respectively. Which work out to 13,920 psi proof pressure. and 10,730 psi service pressure. The math is a couple dozen psi off, I think--because a bar is not exactly 14.5 psi. But close enough for our purposes.
I had it wrong for a long time on service pressure, just as you did. Then I wrote an article on proof and service pressure etc for Shooting Sportsman. They ran it past the Birmingham Proofmaster. His email is the source of my figures above. The Brits have now switched to marking standard proof guns STD with a single crown and magnum (superior) proof with SUP and 2 crowns. No longer using the bar numbers, which are now past history just as are the old tons proofmarks.
