Have him zero one min. higher at 100. Problem solved.
I`ve used Hornadys balistic calculator for some time. It comes very close with various bullets I use in various caliber/velocity/rifles.
BUT, I always shoot to varify...then adjust to suit. With all the variables involved, including shooter, being off 1 moa at 6 is damned close, IMHO.
Just to confirm what the shooting tells me, I just ran numbers on the 162 Amax,160 NPT, and 160 AB through the Hornady calculator.
I know the differences to 600 yards could get lost in my group size but any of these three started at 3200 fps land in pretty much the same group at 500 and 600 yards from my rifle.
