Analytical investigation of the rifling dimension effect on the inner ballistic of weapons

In this study, an analytical method based on energy balance equations has been presented to investigate the effects of rifling dimensions on the axial and angular velocities of the bullet. In this method, gun barrel has been considered as a control volume system that maximum pressure due to the detonation of explosive provides its input energy. Also, bullet velocity can be obtained using the calculation of absorbed energy terms by the system like energy due to friction between rifling and bullet along with taking into account the inner ballistic effective parameters. The obtained results of the presented model revealed that rifling twist-rate and barrel length are two important parameters which influence bullet velocity. Increasing these two effective parameters resulted in increasing bullet velocity over a particular range of values and after that has no important effect on bullet velocity. Comparison of the obtained theoretical results with previous experimental and numerical results in the literature showed a surprising agreement.