The problem that occurs is usually with the Chamber dimensions between 762NATO and .308Winchester, and not the dimensions or pressure of either round!.
Rule of thumb IIRC and I ain't going to wiki anymore tonight

is this but can be overridden with a reliable headspace check.
.308Win ammo in .308Win chamber, gtg.
762NATO military ammo in .308Win chamber, gtg.
.308Win ammo in 762NATO chamber, headspace more generous in NATO chamber meaning softer,thinner cased commercial .308Win brass may, just may, separate. Headspace check is your safety margin here.