Shotgunlover
Thanks for you kind observations.
I have looked at the list of CIP proof pressures. I do know that the 740 bars is the service pressure for standard proof guns. I obviously did not state it in my post correctly.
If proof pressures have changed from 1200 bars to 1370 bars then was the older 1200 bars the equivalent of the old 3 inch proof of 3 1/2 tons per square inch? (To further add a twist: was the 1200 bar pressure measured by transducers or was it LUP?)
1200 bar (transducer) should lead to a 900 bar service pressure (13050 PSI)
My real question was that are American three inch shells at 11500 PSI service pressure safe in older (in proof) 3 inch chambered British guns?
The standard proof service pressure is 10730 PSI. The maximum allowable pressure in individual loads is 850 bar as per the CIP tables(while maintaining a max average pressure of 740 bar).
850 bar is 12328 PSI. So the odd 11500 PSI cartridge of appropriate length in the appropriate chamber ( i.e. 2 3/4 inch shell in 2 3/4 inch chamber) will be handled with ease even by standard proof guns.
So by that "logic" the much heavier proof and stouter build of even older 3" chambered ( 3 1/2 tons per square inch service pressure) British guns should allow them to easily handle American 3 inch shells at 11500 PSI (792 bar, say 800 bar)!
As always ready to be shot down in flames.
Thanks again for your interest and clarification.
All the best
Skeeterbd
