I have a Remington 700 BDL SS .300 Ultra that will print 200 gr Accubonds into 1/2 inch at 100 yards. Less if I have a good day. I have taken a few shots over 500 yards and made them just by using the old holdover method. What system (i.e. turrets or reticle or??) would best serve my rifle on shots out to say, 700 yards? The Leupold Custom looks good as I already have a VX-2. What should I do?