7.62 x 51 or .308

[djcorrell]

There are many more accurate loads with .308 than with NATO rounds.
I have found this to be true with .223 also..;

 

[TenBears]

Found this

 

[JMSTactical]

I would be more concerned with the difference in primers with potential SLAMFIRE...
I have the understanding that the primers in most commercial .308 ammo are much more sensitive than the milsurp ones.
With the M1A/M14/Garand floating firing pins, I would not risk it.
Have heard of people experiencing slamfire just because of bad springs in magazines...
Like I said "This is MY understanding" not presenting this as gospel..