Keep it simple. Nine times out of ten, dancing rounds on paper are optics.

You can check the bases and rings, but you should probably just mount another scope on it. One that you know is good. If that gets your groups back, you know your cross hairs are driffting. Happens a lot. Especially a rifle that rides next to you in the truck. More often then damaged crowning. Not ruling that out, but it's way easier to check the optics first.