Interesting that this is turning up after 2500 rds. I assume you've been cleaning regularly so this isn't just something that has gone unnoticed/been accumulating.
I say this because it seems more and more people want to "run a gun dirty" as long as they can as some form of test.
My experience from years ago: I had a M&P 40, bought brand new, that would literally strip through the jacket of the bullet (I only use FMJ in auto's) to a point that the lands and grooves in the bore would be virtually coated in silver and un-discernible. It only took about 2 mags to do this, and that was starting with a clean, well scrubbed bore... accuracy would go from normal expectation to minute-of-pie-plate in that time.
Smith's answer was that with some barrels the Melonite treatment isn't right, and it ends up being very abrasive. I sent it in, they sent a new one and problem eliminated.
I have one 1.0 Sheild & three 2.0 compact's now... a 4" & 3.6" in 9mm, and a 40. I do notice a silver look to the crown after shooting, as well as a bit of extra fouling in the bore (moreso than my PPQ's, Glocks, P320, FN 509 or Caniks).... but accuracy never suffers no matter how many rounds in a session, and it cleans up with minimal effort.
