In the present paper, results of ballistic tests with 7.62 mm rifle lead bullets impacting and perforating as-received mild steel thin plates at normal incidence are reported. In order to separately investigate the effects of projectile impact velocity and target plate thickness on penetration resistance of the plates, seven impact velocities ranging from 373 to 608 m/s and four plate thicknesses up to 4 mm were considered. A special setup was used in the tests, which allows for the measurement of impact and residual velocities. Moreover, time histories of pro-jectile displacement and velocity as well as resisting force of target plate during the course of penetration were predicted employing the five-stage analytical penetration model of Ravid and Bodner [1]. These histories were analysed and compared with predictions of other penetration models qualitatively. Moreover, experimentally obtained results were compared quantitatively with predicted values and the agreement was found to be reasonable. It is felt, however, that better agreement could have been achieved, if dynamic mechanical properties and consequently a more appropriate constitutive equation had been available.