60,000 CUP sounds very high to me???
This from Wiki- not sure the original source as I didn't go that far but it's not 60K cup according to them
The piezoelectric sensors or transducers NATO and SAAMI use to conduct the actual pressure measurements also differ. This difference in measurement method accounts for upwards of 137.9 MPa (20,000 psi) difference in pressure measurements. This means the NATO EPVAT maximum service pressure of 430 MPa (62,366 psi) for 5.56mm NATO, is reduced by SAAMI to 379.21 MPa (55,000 psi) for .223 Remington.[7] In contrast to SAAMI, the other main civil standards organization C.I.P. defines the maximum service and proof test pressures of the .223 Remington cartridge equal to the 5.56mm NATO.
Sounds like the higher pressure is a result of 3 possible things; thicker brass which means less volume, different place to test the pressure on the brass/chamber, and just the organizations preference and testing protocol for that chambering.
Last edited by dennisinaz; 12/11/08.
