I have a Stevens 200 in 223 that has had a lot of work done to it but it still has the original barrel. I thought the same thing when I saw the bore, it definately does look like chatter marks. When I first saw this I thought to myslef there is no way this is going to shoot but it does.

With mine it doesn't seem to affect it at all. It has been over a month and 250+ rounds since the last cleaning. I normally just boresnake it about every 25-50 rounds. I am sure it is coppered up but it doesn't seem to affect it to much.

If it is shooting as well as you say then I would not do anything until accuracy starts to drop off. You may need to do quite a bit of shooting to lay down the same amount of copper as it had before the thorough cleaning. During the fouling process it might shoot like crap for a period of time. I have a few rimfires that if you clean them very well they need a lot of shooting before they settle back into their groove.

My whole rule of thumb on everything I own is shoot it and only clean it when accuracy starts to degrade. I will wipe down the outside of the firearms and inspect the inside but rarely do an in depth cleaning unless there is a noticeable, repeatable problem with accuracy.

Dolomite