I am going to put a picatinney rail on my 300 win mag. I would like to possibly have the ability to shot up to 1200 yards with this rifle. My scope ia a Leupold Mark 4 4.5-14x 40mm objective, 30mm tube. I was going to use a night force rail and NF low Tac rings. Will I need to get a picatinney rail with a 20 MOA cant/elevation to shoot up to 1200 yards?