I can see you aren't a handloader. I'd be willing to bet that the supposed amount of difference between 7.62 milspec and .308 Win commercial is not nearly as great as the variation of chamber dimension of either between various manufacturers. That is, if you went around taking chamber casts of military production 7.62 rifles throughout the world, the diff between min and max would be much greater than the supposed diff between 7.62 and .308. This whole thing is rather hysterical -- emenating from a bunch of nervous nellies with too much time on their hands. About the only reason to be concerned at all is if you were in a combat situation and excess headspace caused a case separation that jammed the gun (and, believe me, getting the rest of the case out can be a *real* hassle if you don't have a broken shell extractor tool) or if the headspace was so tight that it caused high enough pressures to blow the primer (that's why the military cases have crimped primers, right?) and that jammed the gun. I'd also bet that there is much greater variation between various manufactured milspec 7.62 brass than there is between "7,62 vs .308". Some brittle or thin or steel or thick necked or oversize bullet, or whatever. And, of course, if you are firing mil surplus like the guy in the article, what if you get a deliberately sabotaged round? All that happens normally if you've got a chamber that's a bit large and a case that's a bit small if that that brass streches to fit. This is called "fire-forming" by handloarders. The case then fits your gun and won't stretch any further. If the excess stretching is a lot, you won't get as many reloads before the case cracks. You look for a bright ring on the brass near the base -- and use a paper clip with a little hook on one end to probe the inside for thinness. Anyway, it's much ado about nothing. -- Glad you mentioned the 7.62 CETME round -- look at that, all those flutes in the case wall. hey, if you want fool around, take .45ACP ammo and fire it in your 7.62.... heh, heh, heh. It works, won't hurt the gun. Or fire a .45 Colt thru a .410 shotgun.