I recently bought the Savage 10 BA in .308 and I want to get the NF benchrest 12-42x56 NP-R2. I'm not sure how to pick the scope ring/mounts. I heard that the MOA of the rail needs to match up with the scope or something. I'm not really sure.
If anyone knows anything about this, it would help me out a lot. (I don't want to spend my money on something I can't use.)

The rifles rail is at 0MOA and based off what I've read it seems most rifles are 20MOA?

Thanks!