The invention relates to a perforating gun used for hydraulic fracturing applications in a wellboreand has an outer tube having several recesses of a second kind. The recesses of a second kind are configured to absorb shock waves from a shape charge in the perforating gun to reduce the numbers of cracks that form on the perforating pun. In some embodiments, the recesses of a second kind have a variety of shapes and sizes to aid in the absorption of shock waves.