This study investigates ballistic response of a developed perforated armour plate against 12.7 mm armour piercing tracer projectile. Experimental as well as numerical studies were carried out and the penetration of the projectile through a base aluminium plate was determined with and without the perforated armour plate. The armour piercing projectiles were able to penetrate the base armour plate in successive impacts. However, the combination of the perforated and base armour plates was able to stop the penetration of the armour piercing projectile. A finite element method-based numerical model was developed to investigate the defeating phenomenon of perforated and base armour plate combination. It was observed that the asymmetric impact of the projectile core did not produce large enough bending to fracture the core. However, the high hardness of the developed perforated plate was able to shatter the projectile core in multiple fragments which were then unable to penetrate the base armour plate. Craters of varying depths were observed on the impact side of the base armour plate. The research showed that the selected structural steel can be successfully used for ballistic protection.