The place I hunt whitetails is a big crp field. The crp trees and grass is about 7 foot high so I hunt tripods and ground blinds set up on roads that are about 30 feet wide. The blinds are mostly set where you can shoot 500 yards in either direction down the road. By the time a buck enters the road, you only have about 2 seconds to judge him and make a shot. I have a 300 WM and am shooting the 208 Amaxes at 2900 fps. My question is what distance should I zero my rifle to be most effective since I don't have time to range the deer and make adjustments to my turrets. I missed a huge buck Sunday afternoon by shooting under him and killed a nice one the next day. The deer I killed was at 400 yards and I just spun the turrets real quick without even looking and almost missed him high because I spun it too much. My scope is a Vortex Viper 5-15x44 with a mil dot reticle and was thinking that I could use the reticle for hold over some how. What would you do in this circumstance.