There are many effective parameters in impact mechanics. In this article, the relation between the depth of penetration and the projectile nose shape has been investigated. Projectiles were made of AISI 4340 material with flat, ogive, and hemispherical nose shapes. Semi-infinite targets made of alumina ceramic 99.5 and aluminum 7000. The projectile impact velocity in this experimental test was about 400m/s and the thickness of ceramic and aluminum were 4 and 20mm, respectively. A numerical simulation has been conducted by Abaqus software. The results of the numerical simulation show a good agreement with the empirical observations. The depth of penetration for the flat projectile and ogive projectile was highest and lowest, respectively. The ballistic limit velocity for the flat projectile and ogive projectile was lowest and highest, respectively. Projectile erosion is affected by the ceramic thickness and the shape of the projectile. The amount of this erosion for the flat projectile and ogive projectile was lowest and highest, respectively. Increasing ceramic thickness leads to more erosion in the projectile. Also, the changes of ballistic limit velocity have been determined with the changes of ceramic and backing metal thickness.