One word. Nightforce Check out the NP-R2 reticle. Each of those hash mark are 2moa at 22x. The NXS 5.5-22x scope has 100 mins of elevation travel. The 3.5-15x56mm has 110 min. of travel. The deal is, you mount on a sloped rail. 40 or 45 min of slope puts you near the end of the lower adjustment. Much more than 50 mins of slope, you have to hold under to shoot at 100 yards. You set your zero at whatever, lets say 300 yards. Then you loosen the elevation turret screw and set the turret to zero. Now, you have close to 100 minutes of elevation to crank up. Whatever your choice of scope, the optics must be top notch. As you get close to the edge of of the objective lense, lesser scopes loose brightness. Also, when you return to zero, you want to return to zero. When you buy a scope like this, you are paying for clarity, precision, repeatablity. There are other options, but this is one of the best. Leupold makes some nice high end scopes, so does IOR Valdada
Oh yea. You will also need to go with a rock solid, stress free, mounting system for your scope.