like above prolly a factory rough spot, but with 1K rounds through it, it should have smoothed out by now.

careful with those cleaning rods! i only use plastic or bronze since they are def softer than the metal used in the barrel. rifles it's Boresnake only.
of course you would have to deliberately have to push extremely hard even with a steel cleaning rod to get a good scratch on there, the only place that could cause a scratch is where the brush/mop etc screws onto the rod.