This article presents a large-scale molecular dynamic simulations of wave propagation in a cracked bcc (body centered cubic) iron crystal based on an N-body potential model which gives a good description of an anisotropic elasticity. The crystal is loaded by a stress pulse on its front face and the response is detected on its opposite face. The various shapes, amplitudes, and widths of stress pulse are considered. The simulations are performed also for a central pre-existing Griffith crack. The crack is embedded in a bcc iron crystal having a basic cubic orientation. The acquired results bring important information for further analysis oriented to new NDT nanoscale methods.