If you have an MOA/Adjustible turret and buy a Revic BR4 rangefinder from Gunwerks and all you have to do is input your caliber specific information for the elevations you are at when you zero the rifle and the rangefinder will do the rest. It has a built in weather station, altimeter and does all the corrections for you. You can set it up to give you yardage or MOA adjustments and all you have to do is dial and shoot. I have had one of their rangefinders for the last ten years or so and it has never let me down.