The influence of deviation in the centroid and entry angle of the bullet on its motion inside the barrel

Abstract

The characteristics of a bullet are closely related to its shooting accuracy. In actual shooting, the centroid and entry angle of the bullet always deviate from the ideal state. To study the influence of these two parameters on the movement of the bullet, a finite element model of the bullet movement inside the barrel was built based on a 5.8 mm small-caliber rifle to simulate the actual process of firing bullets. In this model, the pressure load of the real gunpowder gas on the bullet was considered. This model was also verified by experiments and the relative error is less than 1.5%. The result shows that the influence the centroid and entry angle of the bullet are mainly reflected in the amplitude and phase angle of the bullet swing angle. The larger the offsetting distance of cetroid is, the amplitude of the pitch and yaw angle are. The maximum magnitude of amplitude is 0.2°. The difference of swing angle in phase is equal to the difference in offsetting angle. The curve characteristics of different deviation angle are similar to the curve of bullet cetroid effect. The range of the pitch angle is -1°~0.9° and the range of the yaw angle is -0.9°~0.9°.