Magnification range for a general purpose optic on 18" upper

[centerfire]

I had first round hits on IPSC sized targets at 1400yd and 1200yd, with angle and wind, last weekend and my scope never went over 12X. In four days of shooting from 100 to 1500 yards I only used magnification over 12X to check zero at 100 yards. I shot a similar course last year at the same place and only used 10X for the Grendel. I also used a 3X range finder to spot with from my tripod so I wouldn't have to carry a spotter.

I have 30X scopes and I only ever use them turned up to shoot groups on paper during load development.