Corroborative Measurements of the Transverse Motion of a Gun Tube during Firing

摘要

This work presents new measurements of transverse motion of the 30 mm (GAU-8) gun tube first reported at the Third Gun Dynamics Symposium in 1982. The measurements are unique and fully corroborated through the use of two independent measuring devices. In particular, the work discusses three items of interest. First, there definitely exists a 'base-line' transverse tube movement, the cause of which has yet to be determined. The magnitude of this motion is of the same order as that due to other causes intentionally introduced for study. Second, intentionally introducing an eccentric breech mass produces muzzle displacements in good agreement with theoretical models, provided the 'base-line' component is accounted for. Finally, the muzzle rotation created by the moving projectile - though insignificant when operating alone - is strongly coupled to, and capable of greatly modifying the rotation due to other causes. This coupling does not appear to strongly affect muzzle displacement. It is concluded that predictions from gun dynamics models which agree well with displacement measurements, may err greatly when used to predict muzzle rotation, the quality of which is of central interest.