Encyclopedia · Artillery concepts

Rifling, twist, and grooves

Rifling is the pattern of spiral grooves cut into a gun's bore. The lands and grooves impart spin to an elongated projectile, and the rate of twist governs how fast it turns for stable flight.

Also known as: rifling twist, lands and grooves.

RiflingSpiral grooves cut in the bore, leaving raised lands between
PurposeSpin an elongated projectile for stability and accuracy
TwistThe rate at which the grooves turn along the bore
SystemsMany number, width, and depth of grooves distinguish the guns

Spin for stability

Rifling cut a set of spiraling grooves into the bore, leaving raised lands between them. An elongated projectile driven through this bore was made to spin about its long axis, and that spin stabilized it in flight much as it does a rifle bullet, giving rifled guns their far greater range and accuracy over smoothbores.

The rate of twist, and the number, width, and depth of the grooves, varied from one system to another. These features, and the marks the rifling left on a recovered projectile's sabot or band, help identify the gun a projectile was fired from.

On this site

Sources & further reading

← Back to the Encyclopedia