Ballistic properties of two different polymer matrix composites used for military and non-military purposes are investigated in this study. Backside deformation and penetration speed are determined experimentally and numerically for Kevlar 29/Polivnyl Butyral and Polyethylene fiber composites because designing armors for only penetration is not enough for protection. After experimental ballistic tests, a model is constructed using finite element program, Abaqus. The backside deformation and penetration speed are determined numerically. It is found that the experimental and numeric results are in agreement and Polyethylene fiber composite has much better ballistic limit, the backside deformation, and penetration speed than those of Kevlar 29/Polivnyl Butyral composite if areal densities are considered.