Like Hemi and Edge said the gun needs to be shot ! I need to add in 2 of 5 of my large frame guns the charging handle remove metal on the top of the charging handle and on the underside of the U.R. in the groove. Also the rings on the Bolt are a tighter tolorance in the 308 than in the 556, they need to be "Seated" like in a car engine, that is why the "wet lube" condition is always suggested during break in. So run it wet, shoot it, clean it, shoot it again. Get 60 to a 100 rounds through it before you start diagnosting any problems. The gun will wear some metal away. Just do a very good cleaning the first time !