Re: 338 Norma Review By Ward W. Brien
the right hand twist of the barrel imparts, to the bullet, a slight drift to the right. A left twist does the opposite. the greater the twist rate, the more drift.
Coriolus, which is the result of the earth moving under the bullet as it flies, will also cause a bullet to drift to the right in the northern hemisphere, left in the southern. Coriolus effect is best noted by watching the rotation of water as it goes down a sink.
The drift due to spin is probably 4 to 5 times greater than the drift due to coriolus. Spin might account for as much as 12" @ 1000 yards. Coriolus only about ~3".