It is NOT CHATTER, it is not just savage that has these reamer marks. That is what they are. It shows the feed rate that the reamer was sent in at. It is reamed after drilling. Some manufactures lap the bore after reaming but most don't. As you can see. What I would be worried about is if the marks come and go away. That means you have inconsistency in the bore. That will effect how it shoots.

Savage has a better reputation for shooting well over a lot of other brands. But I have had 4 of them that were 3-4moa shooters and they were the ones that got torn apart to be project guns. I expect a factory gun to shoot like dog poop. Then if it doesn't then I got a good one.

And don't bother cleaning the copper out. It will shoot better if you leave it alone. Use a powder solvent and that is all that is needed for a long time. A very clean barrel can shoot like dog poop. Most like to shoot with a consistent layer of copper and fouling.