Time for some folks in this thread to take a deep breath and step away from the keyboard, I think. There are an awful lot of almost-but-not-quite insults and insinuations of lying being flung around. There's no reason for any of it. If you have something practical and factual to say about chrome lined or unlined barrels, say it. If what you have to say is about "the kind of people who own..." then it is probably best left unsaid.
Okay, I'm waiting to hear about all the -MOA groups.
I shoot a lot of competition with the AR and when I see a question like this and the answers I see, boy-o-boy...
There are more Olympic caliber shooters on the internet than in reality.