Determining the most suitable sandwich panel for the selection criteria is vital for the continuity of the protection of the structures. Especially in armor designs for the protection of vehicles produced for defense against external threats, lightness, and cost factors come to the vital factors along with the strength expectations. Sandwich panels, which are employed for mitigating the dynamic effects of external forces on structures, have been produced in many different models, thicknesses, and geometries, and there are many studies in the literature about sandwich panels encompassing their design, performance, and fabrication. In this study, the penetration behavior and changes in the form of Boron Carbide (B4C) coated and uncoated models of stainless-steel surface plate sandwich panels are investigated. Numerical models were developed using CATIA 3D Modeling tools and penetration simulations were performed with 2023R2 Ansys Workbench LS-DYNA. Additional comparative analyses between B4C coated honeycomb core and polyurea coated corrugated sandwich panels from the literature were performed to evaluate the ballistic performance. The ballistic limit velocity of the B4C -coated sandwich panel was 978 m/s, nearly doubling the 527 m/s observed in polyurea-coated panels with deformable penetrators. The high hardness and fracture toughness of B4C caused significant deformation in the projectile, resulting in petal and plug failure modes. Stress redistribution across the impact zone enhanced energy absorption, improved ballistic limit velocity, and increased penetration resistance. The findings highlight B4C’s superiority in achieving lightweight, high-strength ballistic armor. In this study, the penetration behavior, and changes in the form of B4C coated and uncoated models of stainless-steel surface plate sandwich panels, which contain a core formed by combining sinusoidal trapezoidal sheet plates, are numerically investigated against ballistic impacts. The results offer insights into optimizing sandwich panel designs for varying thicknesses, core densities, and material configurations, providing a foundation for advanced protective structures in defense applications.