doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Would You Buy an Out of Proof British Shotgun?

Skeeter, the 740 bars 12ga service pressure is 650 bars crusher converted to the transducer measurement. Likewise, 850 bars proof (crusher) is 960 bars transducer. Once you get the transducer measurement, then you can multiply x 14.5 to get psi.

Miller, the old magnum proof (current superior proof) guns have a service pressure of 1050 bars transducer; 1370 bars proof. I don't think those guns are actually meant for 13K plus loads, but they are proofed to that level. The service pressure figure Roger Hancox gives for one of the 850 bars guns: 10,730 psi. (13,920 psi proof.) From those figures, it's obvious that there's a lot more margin between service pressure and proof pressure under SAAMI rules than there is under CIP rules.