There is some confusion from time to time when a publication will mention a pressure limit as "PSI" or "CUP" or maybe not specify which they mean.
To make it worse, the military documents say "PSI" for the 7.62x51, but their standard was written for CUP.
The two systems are different and cannot be converted one to the other, they way we can convert mph to kph.
Here is a good document that shows the limits in bth systmes for most calibers. The numbers for most calibers are higher in psi than cup, but not always. 357Mag has higher numbers for cup.
For 308Win, you can see 62,000 psi and 52,000 cup. Since the military only use CUP for the 7,62x51, you can see where the idea came from that commercial ammo is hotter.
http://kwk.us/pressures.html
To make it worse, the military documents say "PSI" for the 7.62x51, but their standard was written for CUP.
The two systems are different and cannot be converted one to the other, they way we can convert mph to kph.
Here is a good document that shows the limits in bth systmes for most calibers. The numbers for most calibers are higher in psi than cup, but not always. 357Mag has higher numbers for cup.
For 308Win, you can see 62,000 psi and 52,000 cup. Since the military only use CUP for the 7,62x51, you can see where the idea came from that commercial ammo is hotter.
http://kwk.us/pressures.html
