Re: 308 vs 7.62 Nato
I tend to think the same way that Popgunner says in his post...Not all 7.62x51 is loaded to NATO spec. If it says NATO, then it should pressure out to the NATO limit...but I'd be cautious with some of the oddball country of origin ammo.
Alpo's mention of some hot PMC "NATO" stuff makes me think of pretty much every box of PMC I ever bought. I never had a rifle to run any of their 7.62 through but I have bought PMC in several other calibers. Every one of em had either really lousy brass or they were really hot...or both. In one instance, I bought a bunch of PMC 6.5Swede because that's all I could get at the time...I fired about 20rounds through a very clean & tight M96 that would handle Norma or W-W just fine. With every round I got more nervous that the rifle was about to come apart. Several cases had near head separations and the primers were very flat. I quit using that stuff and pulled them apart to salvage the brass & bullet and junked the powder charge they were using. I also scrounged harder for W-W stuff again. The PMC brass didn't last worth a hill of beans either, even with mild handloads they only lasted for 3 or 4 loadings.
So I'm not sure if you can blame PMC for running higher than normal pressure or if they just had cheap brass. Either one could've caused the sticky bolt problems he experienced with his 7.62 NATO ammo.