Which variable mag range?

[Mule]

Well I have seen a lot of info on scopes and magnification but I really want to know which mag range is the most useful for the 1,000-2,000yd range for a 338/300 gr bullet traveling at 3,000-3,300 fps. I should also clarify that if you have a high power range scope but never use the high mag on it, then please clarify by saying you have a 8-32X but only use up to the 20X

Thanks

Mule