If you are going to mount a scope on a long action using rings only and not even considering offset rings, then you will be mounting your scope relatively far forward.
I found doing it this way on my 700 Classic, where my head sits on the stock made it impossible to a hive proper eye relief. I could not move my scope far enough back to suit my head position.
A one piece rail solves this problem by allowing me to position my s I’ve in the right spot. It doesn’t have the classic lines of simple rings but it is far more adjustable. Plus it’s easier to swap scopes.
This 👍
