The simulations of ballistic range utilizing solid propellant and diaphragm to accelerate the projectile are carried out, using the lumped-parameter method and solid/gas two-phase fluid dynamics codes of both quasi-one-dimensional and two-dimensional axisymmetric methods. Compressible inviscid equations for mass, momentum and energy of gas phase and equations of solid phase used in the two-phase fluid dynamics codes contain the term of interphase properties such as mass of gas generated by solid decomposition, drag between gas and solid phases, and combustion heat. The calculations are started by igniting solid propellants, and terminated when a projectile reaches the accelerator muzzle. For solid propellants charged in the chamber, smokeless gunpowder (NY-500) is used. The simulated results by the different three methods are compared with experimental data for validation. The simulations by the lumped-parameter method roughly predict the experimental breech pressure history and velocity of the projectile, while the pressure wave propagation is not reproduced. The simulated acceleration profiles, the muzzle velocity of the projectile and the breech pressure histories by the quasi-one-dimensional calculation and the two-dimensional axisymmetric calculation are in good agreement with the experimental data. The two-dimensional axisymmetric simulation enables us to predict the behavior of pressure wave propagation in ballistic range.