Spin Drift
Also: Gyroscopic Drift
Lateral bullet drift caused by the gyroscopic precession of a spinning projectile. Always in the direction of the rifling twist.
A right-twist barrel (the common direction) produces a small rightward drift that grows with distance. At 1,000 yards on a typical 6.5 Creedmoor load, spin drift might move impact 8-10 inches right of where it would land without the effect.
Modern ballistic calculators model spin drift automatically. The shooter applies the correction as part of the wind solution or as a separate hold value. Inside 600 yards it’s usually inside the noise floor of other variables.