Coriolis Effect
Apparent deflection of a bullet's flight path caused by Earth's rotation, negligible at normal precision rifle distances but measurable at ELR.
The effect has two components that you can model separately. One is a horizontal deflection that depends on latitude and shot direction, rightward in the northern hemisphere and leftward in the southern. The other is an east-west vertical component called the Eötvös effect.
At 1,000 yards on a typical cartridge, Coriolis might shift impact 1-3 inches. At 2,000 yards on a magnum load, it can reach 8-12 inches, which genuinely matters for ELR. Inside 800 yards, the shift stays small enough that you can safely set it aside.