Depends on what you're hunting and what kind of terrain you'll be in. I have my .375 H&H bolt gun mounted with an old Weaver fixed 1.5.
The only time I carry this gun is when I anticipate going into heavy brush (Visibility less than 100 yds,usually much less), against game that is likely as not to turn on you if threatened.
If I ever take up hunting again, and were to go to say, Elk Hunting here in Arizona, I would probably up the magnification to a four or six power.
I don't like, as a rule, variable powered scopes except maybe on varmint rifles.
I have a heavy barreled custom .280 that I built for prairie dog. It has a variable something by 24 power on it, and if I could have found a fixed 24 for the gun I would have put it on there instead.