I’ll add to what @MSL says which is quite often it isn’t really practical to validate at the distance at which you shoot, firstly finding an easy place to do that is quite hard and second as previously mentioned, the logistics of the target size. My 6.5 is mostly employed between 400-600m and a 600m target would need to be about 2.8m tall... But the logic is correct, if you are normally shooting at between 200-300m, then pick 100m, 200m and 300m.
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