.308 there's no substitute... .308 there's no substitute...Believe it or not, a reverse condition exists with the beloved .308.
By reverse, I mean an increased failure risk in some rifles to use civilian .308 in a NATO spec 7.62X51mm chamber. Some of the hundred plus year old pre 1898 mausers converted to 7.62X51mm come to mind.
My Remington bolt action “Police Special” has a
.308 chamber with a tight throat. You can’t
safely shoot a 7.62x51 NATO in it. There are
headspacing issues between the two specs.