Put together a AR10 in .308 Win. DPMS upper and bolt group. Barrel is a 5 grove from Brownell's, I think Pac-Nor made it for Brownell's. Barrel is smooth, when I cleaned it after install, a 30 cal patch on a 30 cal jag was a tight fit. Using Federal American Eagle AE308D 150 gr FMJBT I'm getting over pressure signs, blowed out primers, pierced primers, ejector marks on the brass. I have some LC93 Match I'm going to try tomorrow. Neither the AE nor the LC showed rifling marks on chambered rounds when extracted. Did show marks from getting into chamber. No bright line around the case head indicating excessive headspace. I didn't check to see if the AE bullet was being set back by chambering, will do that tonight. The LC same mag length cartridge before and after. I'll also check to see if the case mouths of the fired cases will accept a bullet easy.
I'm pulling my hair out on this one guys. I don't want to believe that Federal let overpressure shells out of the factory nor that Brownell's sold a bad barrel. I guess the LC's will tell the tale tomorrow. In the mean time does anybody have any ideas? Thanks guys.