Finite element modeling of bullet-barrel interaction and mechanism analysis of swing phenomenon of bullet

The process of bullet-barrel interaction refers to the following physical process: after the gun is fired, the bullet moves forward under the push of powder gas, interacts with the barrel by extrusion, friction, contact and collision, and finally leaves the barrel. The swing phenomenon of bullet, which has a great influence on the shooting accuracy, is formed in this process. In order to study the formation of swing phenomenon and effect of barrel structure on swing, a finite element simulation model for the interaction process of a sniper rifle is established and calculated in this paper. The movement and stress distribution of bullet and barrel in bullet-barrel interaction process are obtained by simulation calculation, the swing of the bullet under different bore throat taper and rifle type is compared, and the intuitive process of the swing phenomenon of the bullet is obtained. Based on the calculation results, the following conclusions are obtained: Firstly, the dynamic process of bullet swing formation and amplification is obtained. In pre-shooting stage and extrusion stage, because of eccentricity of structure and other reasons, the bullet’s axis deviates in the process of embedding to form initial disturbance, called formation stage. In post-extrusion stage, the initial disturbance is continuously amplified due to the combined action of bullet structure, contact between bullet and barrel, and the pressure of powder gas, finally, the swing phenomenon of bullet is formed, called the amplification stage. Secondly, the effects of bore throat angle and rifle type on bullet swing are obtained.