A method of controlling a dynamic pressure created during detonation of a shaped charge comprises: positioning the shaped charge in a wellbore, wherein the shaped charge comprises a main explosive load, wherein a substance is included in the main explosive load or is positioned adjacent to the main explosive load, wherein the substance increases or decreases the dynamic pressure or increases or decreases the duration of a pressure pulse created during detonation of the shaped charge; whereas a substantially identical shaped charge without the substance does not increase or decrease the dynamic pressure nor increase or decrease the duration of the pressure pulse during detonation. A method of controlling the balance of a portion of a wellbore comprises: positioning the shaped charge in the portion of the wellbore; and creating a desired balance in the portion of the wellbore.