I used a Vari-X II 3X9 for some 25 years on an '06; no trouble killing one of my bucks at 350 with the scope set on 3X.
For no particular reason I put a Simmons 44Mag whatever-to-10 on it. Been shooting 22" steel plates at 500 yards, some, and don't see how more power would really help. I've been able to stay around one MOA by just quartering the plates. Might help if I'd mark an aiming point, I guess. 10X seems to be quite adequate.
As far as I'm concerned, if you're not into serious benchrest or 1,000-yard competition, I'd recommend the good old Loopy VX II, 3X9. I've had the Simmons for five years, and it seems to do just fine, although I haven't fallen off as many mountains with it. Yet.
FWIW, Art