Quote Originally Posted by ireload2 View Post
The 7.62X51 is clearly considered a different cartridge than the .308 Winchester. They use different headspace gauges and they are proofed to different pressure standards.
You are still stuck with that American mindset, NATO proofs to CIP specifications hence the different pressures compared to SAAMI which I know you know and love. As well CIP considers both one and the same.

Excessive headspace in military weapons is preferred so they do not have to be as clean when firing them in the battlefield which when combined with thick military cases is safe. This is especially important in semi-automatic and fully automatic weapons. Look how much machine gun brass expands when fired in chambers that are at almost at NATO Field Reject to aid in the reliability.

Dimitri