What's the upper end magnification where parralax starts to creep in? I favour 2-7X variables. I start to lose sub MOA at 300-400 yards with one of my rifles. 1.5 average groups at 220 yards and 5" at 400 yards. I assumed it was the effect of slight shifts in wind but now wonder if I am seeing the effects of uncorrected parralax at 7X?
