Ballistic performance of engineering materials should be known in selection of the most suitable armor material to protect civilian or military system with the lowest possible weight against various threats. In this study, the ballistic impact characterization of high-strength steels, namely AISI 4340 and DIN 100Cr6, was investigated using 7.62-mm armor piercing (AP) projectiles by considering four hardness levels and five areal densities. The main aim was to examine the effect of hardness and areal density on the ballistic behavior of these steels. Hence, four different heat-treatment schedules were applied to these steels to get different mechanical properties. After ballistic testing, macro and micro examinations of the specimens were carried out to clarify their failure mechanisms. According to the results, the AISI 4340 steel having a hardness of 50 HRC showed the best ballistic performance among the investigated materials.