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"Just to confuse things, you will see older statements which use the term PSI when referring to a CUP reading. In those days the terms were often treated as synonymous because there was nothing else."
I know one guy, in the business, who says you should not shoot .308 Winchester ammo with a maximum SAAMI pressure of 62,000 psi in a military surplus 7.62 NATO rated for only 50,000 psi. What he does not take into account is that the mil-spec was written when crusher gauge readings were reported in psi, before the CUP term was thought up. Crusher gauge maximum pressure for commercial .308 is 52,000 CUP. No real difference. Heck, a .30-06 can go to 68,000 piezo psi. but has seldom been loaded above 48,000 CUP/crusher psi.
I know one guy, in the business, who says you should not shoot .308 Winchester ammo with a maximum SAAMI pressure of 62,000 psi in a military surplus 7.62 NATO rated for only 50,000 psi. What he does not take into account is that the mil-spec was written when crusher gauge readings were reported in psi, before the CUP term was thought up. Crusher gauge maximum pressure for commercial .308 is 52,000 CUP. No real difference. Heck, a .30-06 can go to 68,000 piezo psi. but has seldom been loaded above 48,000 CUP/crusher psi.
