Boyd,
I will be shooting NRA High Power (not bench rest) which means that the maximum range is 1000 yards, not any longer.
Most of the time I will be using the rifle at 200, 300, and 600 yards.
The Picatinny rail means that a Davidson base is probably out. So I'm wondering if the scope itself has sufficient adjustment range for elevation.
Caliber is 6XC with (for 1000 yards) a 115 Sierra MK at about 2800 to 2900. BC of this bullet is over 500. David Tubb claims the wind deflection is the same as a 6.5-284 with 142 grain bullets. I suspect the trajectory would be about like your 210 grain at 2800.
Can you get (with your load) enough elevation within the Nikon scope for 1000 yards?