Analysis of in-bore balloting and control of jump variability

Abstract The variability of projectile jump is the long-term issue to improve weapon accuracy. Nowadays we have many simulation codes to predict Jump. However, these codes cannot explain explicitly how the variability of jump arises. The aims of this paper are, 1) to give fundamental explanations for the variability of Jump, and 2) to offer design factors to make the variability of Jump less. The model presented here was formulated in accordance with the transition of the system in reverse way commencing from the target impact stage to the chambering stage. Objects of the simulation are generic 120 mm smooth bore and long rod system which are extremely simplified to the vibration of tube, the spring effect by sabot, and the free-ends beam of penetrator. Parametric calculations clarified that high Jump-variability is generated only when the last rebound is on the muzzle line. This particular state of rebound is achieved by many combinations of input-variable. Guide map named JV-Chart is proposed to show the high Jump-variability zone.