Those scuff marks are the contact points of the ring and the top of the rifle action and the bottom the ring. In the picture above if you look close at the alignment boss above the clamp nut you will see the second contact point.

Here is a picture of the front ring.

You can see two contact marks where they should be. Except it appears the front alignment boss might be bottoming.

I have never seen a Ruger rifle that has been scoped and shot for a while that doesn't have these contact marks. I'm not talkeing about looking at four or five rifle here. I'm talking about a couple of hundred worked on in my career. Not alot in some gunsmiths career but more than enough to form a clear opinion.

As to jiggling rings; well yes that well work, but a babbit is better.