While in Tanzania I had the opportunity to hunt with a M-70 in .375 which was topped with a Leupold 2.5-8X with extension rings to keep the ocular from becoming stuck in one's forehead. This was a nice setup, and the scope allowed the hunter to see well enough to fully appreciate the versatility of the .375 cartridge. If I had a SAKO .375, I think I would get a base that converted the tapered dovetailed receiver to a Picatinny rail, since this provides the greatest latitude for mounting variable power scopes which typically have long ocular housings. Such conversions can be had from Roedale Precision (Germany), Valdada, and US Optics, so it won't be a cheap option, but it will be a beneficial one.
From the Roedale Precision webpage:
Picatinny rail for Sako
This Picatinny rail for Sako systems fits on the integrated Sako dovetail Optilock. It allows the use of Picatinny-type ZFR mounts, instead of the not always reliable Optilock mounts. It allows you to have a Picatinny mounting system on your Sako. Suits hunting type scopes with limited adjustment range.
Available in two different versions:
- Short: Fits Sako S491, M591, L461, L579 M74 (.222-308) 75 I, 75 III, 85XS, 85S actions upto .308win
- Long: Fits Sako L691, L691 Mag, L61 Finnbear, L579, M74 (.308-.375) 75 III, 75SM, 75 IV, 75 V. Sako 85SM, 85M, 85L, 85XL - MA05S, MA05SM, TRG-S