Krupski S.J., Taylor B.R., Audino F.J. Measurement of rifling twist in gun tubes

(Крупский C.И., Тейлор Б.Р., Аудино Ф.И. Измерение шага нарезов в артиллерийских стволах).Technical report. Watervliet, N.Y.: Watervliet arsenal. 1976. – 29 р. (англ. яз.)Methods presently employed for determining conformance of rifling twist in gun tubes do not provide for direct measurement. The machine tooling used in manufacturing is calibrated and it is assumed the rifling twist produced in the gun tube is an acceptable reproduction of the machine tooling. New Inspection equipment has been designed and developed which provides a practical and effective means for direct measurement of rifling twist in gun tubes.