Dirty barrel = more accurate barrel?

[Llama Bob]

could be, but i don't believe that. assuming we're talking about a decent match grade, lapped barrel, i don't think the bore diameter changes enough to allow the bullet to alter its path. i also don't believe fouling would solve that problem if it existed.

I'm talking about factory barrels. Good match barrels should start accurate, see a small POI shift when dirty, and stay accurate for a very long time.