Entirely true, crusher measurements and piezo electric transducer measurements aren't convertible. Few people realize how serious a problem the conversion to piezo has been. It's bad enough with ordinary cartridges that had pressure standards in CUP to begin with, but at least CUP and PSI measure the same thing with a different yardstick - radial (sidewall) chamber pressure. With the cartridges that we discuss on this forum - the British flanged nitro expresses intended for use in double rifles - its much worse, because the British didn't measure chamber pressure at all. They standardized on bolt thrust, expressed in long tons, instead. No one seemed to understand this when CIP converted to piezo, and much of the factory nitro express ammunition loaded since then (and much of the handloading data developed and tested in piezo guns) has been overloaded. A few doubles have been blown up, and quite a few damaged.
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