The stress response of an artillery barrel when fired is principally due to loading from gas pressure and contact force with the projectile. This paper reports a research project in which a dynamic model of a barrel and a projectile was established in order to investigate the stress response of an artillery barrel. Calculations of propellant gas pressure, in part determined by the position of the moving projectile, were carried out using user-defined subroutines developed in the abaqus/explicit software. Numerical simulations of the dynamic loading process of the barrel were carried out to examine the radial effects of gas pressures. Using this methodology, the evolution of barrel stress distributions was simulated, providing a visualized representation of the barrel's dynamic response. The calculated dynamic stress due to projectile contact alone can reach a peak value of 181 MPa, reflecting the significant effect of contact force on the barrel's dynamic response. Following this, the effect of propellant combustion on the dynamic response was explored, and the results obtained showed that higher initial temperatures produced more pronounced dynamic responses. Moreover, significant differences in stress distributions computed for the barrel revealed deficiencies in the static strength theory for evaluating the operating conditions, due in part to the omission of contact force and other dynamic effects. This paper proposes an alternative investigative approach for evaluating the dynamic stress response of barrels during the initial phases of the ballistics process, and provides information that should lead to updates and improvements of barrel strength theory, ultimately leading to better predictions of firing reliability and operator safety.