I've got basically the same setup you've got, a stainless Sako 75 chambered in .300 Wby mag. I've got a 3-9X40 Zeiss Conquest on mine in the Optilock mounts. I'm very happy with both gun and scope. I've also got a 7mm Mag Sako 75 with a 4.5-14x44 Conquest also in Optilock mounts. However, right now I've got a Leupold VX-III 3.5-10X40 on order to replace the 4.5-14 Conquest. I just haven't been as happy with the 4.5-14. I think you're just kidding yourself if you think you need a high magnification scope (over about 10 power) on a big game hunting rifle and I don't think you need the parallax adjustment either. The 4.5-14 Conquest I have has the side parallax adjustment and to me it's just a nuisance.

As some others have said, the Optilocks are the way to go and make sure you go with the lowest ones. I've tried Leupold and Millets also, but they just don't hold a candle to the Optilocks.