EDgun West's Airgun Calculators

Twist Rate Calculator

The twist rate calculator will assist you in determining the stability of a bullet when fired from a particular rifled barrel. It has been long-established that the bullet should spin or rotate along the longitudinal axis to c long travel distances while maintaining stability. This spin on a bullet is induced by introducing grooves in the barrel. The bullet stability is varied with different barrels and is estimated using the Greenhill formula or the Miller twist rule.

Twist Rate Calculator