Of course, I'm still thinking about this business of when a quantified pressure from one source in one situation is not the same pressure from another source in another situation, as per 2-pipes below:

Quote:
To go back to basics as you say R'Man I think you would find if you placed a hydraulic piston hooked to the hinge pin with its ram pushing against the standing breech, centered on the firing pin hole & having same bore as the internals of the case & pumped up the pressure equal to that developed by firing a standard shell with proper gauges hooked up to measure deflection of breech, hinge pin or any other critical part, you would find the deflection greater than firing the shell which produced identical "Peak" pressure. Now this will be because the peak falls away before its full effect can act upon the breech.


Lot to take in here!!

jack