"Wind" is whatever factors cause 200 yard groups to be greater than twice 100 yard groups, and includes wind drift and mirage. ("Wind" becomes exponentially more important as range increases; thus this speaks to ranges of ~300 yards or less.) Calculations of the effect of "Wind" on group size show that with no "Wind", 5/100 (5 shot 100 yard), group size would decrease 4%, 10/100 5%, 5/200 13% and 10/200 16%. "Wind" is not a great contributor to inaccuracy. "Goal to Go!" by Warren Page, 1957 Gun Digest pg 83 "…In the finest accuracy shooting ever done by a large entry, that at Johnstown last Labor Day, in the hundred-yard 10-round matches, 28 of 148 riflemen averaged less than half a minute of angle. But for the fifty-shot series at twice this yardage, only two of 146, Sam Clark and myself, could stay under the half-minute mark. At 200 even the top ten shots averaged almost 30 per cent bigger groups, relatively, than they had at the shorter range, and among the less inspired trigger-squeezers the fall-off was far greater….Reason? Sighting problems, wind and mirage, which are essentially human rather than equipment problems. Of this inter-related pair, wind drift is far less a bogeyman to the accuracy bug than target displacement by mirage. I can remember only a few shoots (and they were conducted in minor gales) where the sights were free of mirage waves, yet bullet paths were bent and the groups enlarged by wind alone…. As a source of accuracy error, most of us cranks consider mirage four or five times as wind in normal quantities and velocities."
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