AR556 bolt lugs

Bear with me guys, I'm not the best on nomenclature. Have a new Ruger ar556. Put around 100 rounds through it, no problems. Saw on the carriage where firing pin is showing. So I bought a Bravo co. Complete BCG an ran 200 rounds through it, no problems. When I went to clean it I noticed on the outside of chamber where bolt lugs touch it to lock in place there are scratch marks with a tiny ridge where bolt stops when locked up. I have head space gauges on the way from Brownells. Is this type of wear normal. I used to have a s&w m&p 15 sportll and don't remember seeing that on that ar. Should i be concerned or keep shooting to see if it gets worse. Would it be necessary to take barrel off and carfully sand off ridge an polish that area?
All responses are always helpfull, Thanks, Richard.

Pictures would be nice

Both of those observations could be completely normal.

More detail and pictures are needed to say for sure.