Fine Adjustment for Earth Rotation

The Earth is a spinning ball, and a consequence of this is that you and your target are not moving at exactly the same speed.

• In the N hemisphere a shot to the N will go a little right and a shot to the S will go a little left (as higher latitudes are nearer the Earth’s axis, so the spinning makes them move more slowly).

• In the S hemisphere the reverse happens.

• The effect of the above increases with greater latitude and is 0 at the equator.

• In either hemisphere a shot to the E goes a little down (as the target is rising like the Sun), and a shot to the W goes a little up.

These effects increase with range:

• because the range takes in more of the Earth’s curvature, and

• because the bullet takes longer to reach the target, giving the target more time to move.

In due course a calculator will be provided along with tables for ranges people use.