Ok so I going to be shooting in a week at about 250 to 300 yds. I will be using a ndm-86 gas operated semi automatic in 308 my loads are 168grn sierra matchking lake city match brass and 41.5grns of imr 4895. My scope has 1/2 moa adjustment and is zeroed at 100 yds how many clicks should get me in the range. Obviously it will not be exact as there will be other factors I am just trying to get it close. I will be at a machine gun shoot and this is hopefully going to be my tanerite killer. Also the elevation will be flat but shooting over a valley to targets on the other side.