Those cases have seen some hard use, but the circles are not from use in a firearm.
The very lightly impressed circles (red) are from the bunter (tool used to impress the head stamp) being modified over time. At one time, those circles were raised points on the bunter, and would have left an impression like the deeper circles (green). However, they have been ground off and polished.
The yellow arrows with a red outline point to an impression of the ejector hole in the bolt, from being fired with a hot load.
