Good afternoon and Happy Fourth of July week! I picked up a Citori 725 Sporting 2 weeks ago. Shot three rounds of trap through it, cleaned it, cased it and opened it up today...it has perfectly spaced apart "white" spots down both barrels. It looks like it's polka-dotted. They're not white, white. They're more like gray. Like a finger print. However, they're not prints. And they won't wipe off. Any ideas? Never seen this on any of my sporting guns. I'll post two pics as well. Notice how the dots alternate barrels and work their way all the way down to the end?