|This report details the steps needed to formulate an engineering design equation to address the potential for breaching of concrete masonry walls in between grout cells when subjected to blast loading. Prior to the beginning of this research effort, large-scale dynamic tests were performed by Air Force Research Laboratory. These tests were used to verify finite element models created using LS-DYNA. A comparisons of finite element models and testing were performed to help verify the finite element model analysis. A short suitability study was carried out to understand the cause of the breaching shear in concrete masonry walls. Two analytical models were created to provide an understanding of the mechanics of the breaching. A comparison of the FEM and analytical models were carried out. Finally, a design shear equation was formulated, and a maximum pressure for partially grouted construction was found.