With 2FP (second focal plane) scopes, one can normally only be accurate at one power...usually the highest setting. The reticle size does not change (relative to the target) when power settings are increased or decreased. You could mathematically figure out the subtensions I guess, or just shoot and make a note at all settings and ranges. With FFP (1st focal plane) scopes, this is not an issue. The reticle changes (relative to the target) so as to keep the subtensions equal. The Meopro is a 2FP scope. Therefore, at high power you are good to go. I apologize if my explanation is confusing. A mind is a terrible thing to use...in my case "not use". LOL