Just picked up a used Sig p226.  As with most of my handguns, there is noticeable wear to the barrel.  A little bit of barrel finish wear doesn't bother me at all, but what bothers me is the top, "flat" portion of the barrel that is exposed at the ejection port.  This top flat portion is flat for 95% of the surface area, but towards the rear there is a noticeable slope.  You can also see the break point between flat and sloped.  Has anyone ever noticed this slope and do you think it's anything to worry about?

Slope is normal.