Eötvös Effect
Definition
The vertical component of the Coriolis effect on a bullet. Increases impact elevation for eastward-fired shots, decreases it for westward-fired shots. Typically less than 1 cm at 1,000 m for rifle calibres.
- Direction dependence
- Raises impact for eastward shots, lowers for westward
- Cause
- Vertical component of the Coriolis effect
- Typical magnitude
- Under 1 cm at 1,000 m for rifle calibres
Common questions
Why does firing direction change the size of the Eötvös effect?+
The Coriolis effect from Earth's rotation has a vertical component whose sign depends on the bullet's compass heading relative to Earth's spin axis, so an eastward shot experiences a small lift while a westward shot experiences a small drop.
At what range does the Eötvös effect become practically relevant?+
Because it is typically under a centimetre even at 1,000 metres, it matters mainly in extreme long-range precision shooting or ballistic reconstruction, where every millimetre of correction is stacked with other factors like spin drift.
Related terms
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- Coriolis Effect
- Apparent deflection of a moving body due to the rotation of the Earth. In the Northern Hemisphere, deflects projectiles to the right...
- Fire Control System (FCS)
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- Laser Rangefinder (LRF)
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- Magnus Effect
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- Miliradian (Mil)
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- MOA (Minute of Angle)
- 1/60 of a degree of arc. Equal to approximately 2.908 cm (1.047 inches) at 100 m. Used in civilian and some law...
- Spin Drift
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