Ballistic protection is a matter of interest requested by civilian as well as military needs. The last decade has witnessed an increase in the use of light weight and efficient armour systems. These panels may be used for body protection as well as light vehicle protection against small calibres or to enhance the protection level of heavier vehicles with decreasing or maintaining their weight penalty. Ultra high molecular weight polyethylene is a material of interest for light weight armour applications. The authors designed panels made of hot-pressed Tensylon ® in different configurations with thin steel sheets as a backing and shield protection. Comparison of their ballistic performance to the theory predictions reveals the improved ballistic response of the panels. In addition, a non-pressed Tensylon ® panel has been tested in order to facilitate the observations of the failure mechanisms inside the panels. Even if not suitable for practical use, such non-pressed panels clearly reveal the dynamic processes at micro-scale that occur during the impact. The failure mechanisms of the material under bullet penetration are discussed based on photography, optical microscopy and scanning electron microscopy. The supposed effects of the panel pressing are discussed based on the observed difference between pressed and non-pressed structures ballistic response.