In this paper, the sabot separation process in super/hypersonic flight from 600 to 2501 m/s is numerically investigated by using CFD and RBD (Rigid Body Dynamics). Firstly, the motion of sabot separation is calculated for validating our in-house code. CFD-RBD code shows good agreements with Mehmet’s experiment. Secondary, the effects of exit velocity from muzzle are examined. While all sabot velocities differ, sabot separations indicate the same trajectory. The variation of sabot velocity can be eliminated by non-dimensionalization considering exit velocity. Finally, the effects of sabot material, which means mass density, are investigated with railgun acceleration condition. Sabot separation shows different motion completely depending on sabot material. However, non-dimensionalization eliminates the effect of sabot material on separation. Proposed non-dimensionalization method can represent the various sabot separation motions in unique one trajectory, considering exit velocity and sabot density in time term.