Re: What do you shoot .308 or 7.62 in dpms??
.308 are specd to run at a slightly higher pressure than 7.62x51, something like 62,000psi vs 51,000psi. If the barrel is marked .308, you should be just fine to shoot either is the general consensus.
My Noveske N6 is marked 7.62x51, and I shoot the shit out of .308. As a matter of fact that is all I shoot (that's a lie, I have a few battle packs of 7.62x51 in the safe). Any reputable manufacturer's barrel should be able to handle either.
You won't find "NATO" .308 ammo as far as I know (I am far from an expert) you will find NATO 7.62x51, or reloads of .308 that use old NATO brass.
I think if your just plinking at steel or paper, or stocking up for the zombie apocalypse then the cheaper bulk 7.62x51 is fine just be prepared to clean it a little more often (I have found it to be dirtier regardless of manufacturer). If your looking for accuracy, and consistency look at FGMM (federal gold medal match in 168gr or 175gr, or something similar from someone like Southwest Ammo who is competitive in pricing, and quality from what I have heard around here. I am far from an expert on these subjects, but I hope I have helped.