The Coriolis Effect
Long Range Shooting
It has been alleged that the Coriolis Effect plays a large part in accurate sharp shooting over long distances. However, we find several online references where claimed sniper veterans have stated that they have never taken the Coriolis Effect into account when shooting. We are pointed to the U.S. Marine Corps Sniping Manual, which does not mention the Coriolis Effect anywhere in the text at all.
U.S. Marine Corps Sniping Manual
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Misleading References
The internet is rife with references that the Coriolis Effect is actively used, but this is an assumption without demonstration.
The World’s Longest Sniper Kill: The Enemy Shot Dead at 3,871 Yards (Over 2 Miles Away)
“ To understand the complexity of the shot, it’s best to start with a sniper maxim: sniping is weaponized math. Although a .50 caliber sniper rifle bullet can fly as far as five miles, a host of factors including gravity, wind speed and direction, altitude, barometric pressure, humidity and even the Coriolis Effect act upon the bullet as it travels. Even worse, these effects increase the farther the bullet travels. A successful sniper team operating at extreme distances must do its best to predict exactly how these factors will affect the bullet and calculate how to get the bullet back onto target. ”
This quote actually says "these are the factors that will affect the bullet," rather than "these are the factors that the sniper accounted for."
Other authors may be under the impression that snipers need to actively account for the Coriolis Effect, but they are mistaken.
Wind Currents
The Wind Currents are put into gradual motion by the attraction of the Northern and Southern Celestial Systems, which are grinding against each other as gears at the equator line.
Water Currents
The rotation of small scale liquids in opposing hemispheres was debunked by Snopes.
As for water currents on a large scale; they're simply gradually put into motion by the winds. Water currents in the Northern Hemisphere will tend to rotate in one direction while currents in the Southern Hemisphere will tend to turn in another direction.