I have a 308 chamber. While I don't regularly shoot surplus ammo, I will on the occasion, but the 308 chamber is the one that can handle the higher pressure, the 7.62nato is rated for less. Look at all the guys shooting 5.56 out of a 223 chamber. Have you ever heard of anything bad happening? I haven't. Ultimately, this is a personal preference. If I were in your position, I wouldn't think twice about it, I'd shoot whatever works well. In that sense, don't buy an entire case of anything, shoot a little, and inspect all of the spent brass for bulges, flattened or popped out primers. You should also check around on ar15.com and DPMS's own forum for sure, it is www.dpmsinc.com/forum. I'm sure the same issue has been addressed many times. You could always eliminate any issue in question, by reloading your own ammo.