Ruger rings are the worst, sometimes the receivers aren't straight either. You should see how crooked my 270 is. Clamp the rings to the bar to get them half straight then tighten them down to the bases, see if that helps.
I might as well just put the scope in the rings, tighten it down, and then tighten the base.
I think that would place unwanted stress on the optic.
Don't think its been mentioned yet, but perhaps you should consider epoxy-bedding the scope in.



























