Wind Flags
Downrange flags or indicators that reveal wind speed and direction at points along the bullet's path to the target.
Wind flags are physical indicators, from simple cloth flags to purpose-built daisy-wheel and propeller units, placed at intervals downrange so the shooter can read the wind where the bullet actually flies rather than only at the firing line. Their angle and motion give a quick estimate of speed and direction, which feeds directly into wind-reading and the math of holding off.
Because wind rarely blows the same everywhere along the path, a line of flags lets the shooter judge the wind-value at each segment and weight the corrections accordingly. Where flags are not allowed or not present, shooters fall back on mirage, vegetation, and other natural indicators to estimate the windage correction needed for the shot.