This book presents the computational methods for solving the solid mechanic problems in the oil well perforator design. Both Lagrangian and Eulerian methods are used to solve the pertinent stress-strain equations and the shock wave running through the materials. Seven good performance oil well perforators and two conical shaped charges for defeating the reactive armor are included in this book as references. The computer programs written in Fortran for the calculation of high explosive burn time and burn distance, shear modulus and yield strength for many materials, as well as MATLAB plotting programs for many perforators are available online as supplementary materials for the book--.