As said...measure where you found this "corrosion", clean it and look again. Yes, it may be corrosion but it is pretty early in life for what looks like that type of pitting. Actually, just push a dry patch or brush thru and see if the "pitting" is in the same place.
Bore scopes are very handy tools...IMO, primarily to eval state of cleanliness/dirtiness and the effectiveness of your cleaning regime. But we have all pretty much seen stuff that someone is stressing over as pitting and it turns out to be lint from patches or some other crap sitting on the surface fo the steel.
If it is actual pitting after only 200 rounds of 6.5 CM....and you don't live in a tropical rain forest...I'd take it up with whoever you bought the rifle from (assume you bought it new)