It's 308W. Like you, I'm assuming it was either how it was cut the first time or a flaw in the composition of the steel.
But back to the topic at hand, I still maintain my vote for .243. I'm having a ball with .243AI.
Op didn't mention reloading which would play a factor if 243 is chosen. There are plenty of various hunting loads available from the factory but not much in the way of target loads.