The projectile engraving process directly influences the projectile motion in‐bore and impacts the firing accuracy, firing safety, and barrel life of the gun. For this reason, attention has been focused on this research topic. To address the limitations of the “instantaneous engraving” hypothesis adopted in the classical interior ballistic theory, the VUAMP user subroutine, one of ABAQUS's secondary development interfaces, is utilized in this paper to realize the modeling and numerical simulation of a coupled dynamics model of the projectile engraving process. In addition to facilitating engineering applications, a polynomial fitting formula of the engraving resistance obtained by simulation is proposed and then used as a supplement to establish a closed and solvable interior ballistic model considering the projectile engraving process. By comparing with test data, the simulation accuracy of the coupled dynamics model is verified. Simulation results reveal that the engraving process takes 3.8 ms, accounting for 26% of the whole launch process, which takes 14.6 ms, demonstrating that the process is not instantaneous. The results of this paper can serve as a reference for future studies on the coupled solution of the projectile engraving process and interior ballistics of guns or gun‐like equipment.