Quote:Mirage! Yup, that is the operative word.
How are you going to correct for elevation and/or wind? Dial the turret or use the reticle? How far are you going to shoot? I use the reticle on both of my .204 rifles so I went with 4.5-14 power. A 14x scope is plenty out to the max. range for my reticle (550 yards on 14x). In fact, 14x will take you out to longer ranges if you have a way to correct for drop.
On my primary long range rifle I run a 5.5-22 Nightforce scope, and I dial the corrections. My brother uses Leupold 6.5-20X scopes. In mirage, we both turn the scope down. I also find myself constantly going up and down in power to find the target because of the small FOV. My brother leaves his scope on about 16x unless he shoots past 700-800 yards.
FWIW, I used a 7mm Rem Mag with a Nightforce 3.5-15.5 scope a bit one summer when I was trying to get into the 1000 yard club. While not ideal, 15.5 power is workable in the 1000 yard range.