I am not disagreeing, just curious . . . Do savages commonly lack parallelism between the action top and the bore of the barrel to the point that normal scopes, bases and rings can be 12" off at 100y - wow, glad I haven't seen this. I wonder what the frequency is?
I don’t really know the answer, as I’m not a gunsmith. My dad’s model 110 .270 is roughly 30 years old. I was stumped on the issue just like the OP and hated the idea of shimming with a beer can like a gunsmith recommended to me. Talked to another gunsmith locally and he’d seen it before on model 110s of the same vintage and turned me onto the rings with the cam-shaped inserts. “Having seen it before” may or may not mean it’s a widespread issue, but I gave it a try and it’s shot great ever since. YMMV