And don't forget the correct sighing in process for the offset scope mount.
The attached rendering is the sight picture setup virtually all of us here at SP use for Swissicon Rifles as well as for the M1D Garandicon Sniper.

The offset of the mount is 11/16", so leave it at exactly that POI at 100 yards and it will remain so out to 1,000 yards. No need to zero it on the bullseye. If you do, the POI will change the further out your target is.

If you can tell the difference beyond 200 yards, you're a much better shot than I am, Gunga Dihn.
scope you choose, remember that the lower and closer to the axis of the bore, the better.