A rotating Round Earth model predicts that bodies which move through the air will be appear to be deflected Eastwards or Westwards in their path of movement due to the rotation of the earth. This effect has been termed the "Coriolis Effect."

The Coriolis Effect, however, is a fictitious effect that is not, and has never been, demonstrated with experimental evidence. Its proponents are unable to show that this effect has ever been detected or that it is truly necessary to account for in various operations. The evidence for this effect appears to be based entirely on 'common knowledge', on how things 'should be', and by authors who make 'predictions'; but all articles and documents presented in favor of the "Coriolis Effect" are without reference to, or demonstration of, the critical and necessary experimental evidence to directly prove the matter.

Artillery

It has been alleged that the Coriolis Effect plays a part in the ballistic trajectory of artillery, and that artillerymen must account for it for accuracy. We are presented with military instructions and range tables for accounting for the Coriolis Effect, and so, it is speculated, the Coriolis Effect must be a real effect.

U.S. Army Artillery Coriolis Table Example

We are directed to the table from following document:

The Production of Firing Tables for Cannon Artillery (1967)
http://www.dtic.mil/dtic/tr/fulltext/u2/826735.pdf

Pg 103, Table H, Corrections to Range, in Meters, to Compensate for the Rotation of Earth:

When Coriolis Effect proponents are challenged on the accuracy of this table, the proponents proclaim that if it were incorrect then artillery and artillerymen would be routinely inaccurate and miss their targets, and how could that be the case?

Artillery Ballistics Not Accurate

From the the introduction of the above paper we read that military artillery, which is purported to require adjustments for the "Coriolis Effect," is indeed, routinely inaccurate. The first round generally misses its target. Only after missing a number of times, and then adjusting the alignment of the cannon to compensate, does the artilleryman hit his or her target.

From the above 1967 artillery paper we read:

“ Ideally, a firing table enables the artilleryman to solve his fire problem and to hit the target with the first round fired. In the present state of the art, this goal is seldom achieved, except coincidentally. The use of one or more forward observers, in conjunction with the use of a firing table, enables the artilleryman to adjust his fire and hit the target with the third or fourth round fired. ”

In another artillery paper from 1973, we read a similar quote:

http://www.dtic.mil/dtic/tr/fulltext/u2/909704.pdf

“ When today's field artillery firing tables are used with today's approved delivery techniques [as described in VM 6-401], accurate fire can be brought to bear on targets.

Such a statement can only be made because today's approved delivery techniques recognize that many errors (both precision and bias errors) exist and those techniques arc designed to minimize these errors. The techniques are not designed to produce first round hits, nor does the statement above infer that such hits can be achieved. ”

In 2016 a claimed expert named Guy Schuchman says that, despite GPS and modern improvements, the same problems exist today:

“ It's extremely rare for the first round to hit the target. It's just too much data which not all of it can be measured in 100% accuracy and human errors are quite common: small offsets in calculating the coordinates of the target or the gun, small errors in calibration, humidity of the explosive propellant, etc.. The first round is just a test round. When it falls near the target it's the artillery observer's job to see how far and in what offset did it hit away from the target and provide the FDC with the data. ”

A 2017 paper by Australia's Armament Research Service admits the same:

https://www.icrc.org/en/download/file/36109/ares-icrc-report-indirect-fire.pdf

“ Even though great effort is made to calculate the effect of environmental and ballistic variables, an unguided artillery projectile will not reliably strike the exact point at which it is aimed. Although artillerymen strive for first round accuracy, this will still be measured in tens of meters, and in deliberate targeting or combat engagements this introduces a degree of uncertainty when assessing the safety of friendly forces and non-combatants. Properly employed, artillery gun and mortar projectiles and rockets land in a predictable area (accuracy) in a non-predictable fashion (precision), and in common with small arms fire (especially machine guns), the employment of artillery systems yields a ‘beaten zone’ or field of fire into which rounds will fall. This zone is generally cigar-shaped with the long axis falling along the line from the gun to the target, as deviation tends to occur in range rather than azimuth. The length and breadth of the zone is range dependent, as with greater range, external factors have more time to exert influence on the projectile flight. ”

Sharp Shooting

It has been alleged that the Coriolis Effect also plays a 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

U.S. Marine Corps Sniping Manual
1981 Version Full Text
2016 Version Full Text

The sniper must know the general principles of: perspective, vanishing point, perspective drawing, delineation, and geographical areas of intelligence operations. However, the words "Coriolis" or "Coriolis Effect," do not appear anywhere in the U.S. Marine Corps Sniping Manual.

The curious reader might ponder why the U.S. Marine Corps does not teach this allegedly important effect to its snipers.

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)
https://nationalinterest.org/blog/the-buzz/the-worlds-longest-sniper-kill-the-enemy-shot-dead-3871-24141

“ 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." One is a commentary by the author and the other is a depiction of process. The reader should be able to see and understand that there is a difference.

Water Currents

The rotation of small scale liquids in opposing hemispheres was debunked by Snopes.

Addendum

Many of these discussions against the Round Earth proponent are often and trivially won with a simple request of evidence. 'Mountains' of evidence are claimed to exist for phenomena such as this, yet when questioned in a simple matter on the necessary demonstration, we find that the response is, to any reasonable mind, insufficient.