Ricksmith: Amen to a human holding to within 5/16" or even 5/8" at 500 yards.
Let alone all the atmospheric conditions that would negate that tiny difference in "built in" dispersion of the P.O.I.
I have a phone call in now for a Nikon 6.5x20 (used but like new) and if I am not mistaken they are about the only folks (Nikon) that make a scope that I own that adjusts to 1/8"?
I think my Unertl BV-20 adjusts in 1/8" or 1/8th M.O.A. IIRC.
Scopes, no matter if they are 1/4" adjustable or 1/8" adjustable are just to dang expensive anymore - here I am dealing on a "used" scope for a new Rifle.
Times have sure changed in the retail scope world.
Hold into the wind
VarmintGuy