The RevDoc's synopsis fits well with what I've read of 850 Bar European (CIP) proof vs. service pressure. Feller that had what I can only refer to now as the defunct "Spanish gun site" on the web said 2/3 of proof for service pressure or about 8000psi. I don't remember ever reading anywhere a "rule of thumb" that proof pressure is customarily 150% of anticipated service pressure but that's the way it appears to work out with Sherman Bell's Remington (SAAMI?) proof pills: roughly 18000psi at proof for anticipated service loads yielding maximum of 11000+psi. The French "triple palm" proof pressure appears to be about the same as current SAAMI: 20Kpsi against 18Kpsi.

jack