The referred NATO round was the 7.62mm x 51mm, also known in the commercial world, as the Winchester .308.
The .30-06 has an effective range of 1000 yds., and is gloriously tied to the M1 Garand.
The .308 has an effective range of 500 yds., and is the round that fed that other great rifle, the M-14 Springfield.
The 7.62 x 39mm was NEVER a NATO round, but was employed by the Soviet Union and the Soviet Bloc nations. It is the weapon of terrorists the world over.
I refuse to own any and all models of any rifle that chambers that cartridge, because it is un-American, SHTF folks or not.
I still believe that, an American-design lever action rifle, is superior. Why? “Mr.AK 7.62 by 39” can have a spray and pray day all day long, but that day can be interrupted by “Mr. Guide Gun 45-70”, just once, to be a bad day.
The AK-47 is probably the most reliable weapon of its class. Just because the commies invented it one shouldn't eliminate it from one's arsenal. Besides, when the SHTF, I'd want something chambering 5.56 and 7.62 x 39. You never know what kind of ammo you'll pick along the way.