High Explosive Shell, Concrete Piercing Fuze (CP). The CP fuze is of special, heavy metal construction for use against concrete targets. These fuzes come in two types: non delay to clear away rubble and shatter effects and a delay type (0.025 seconds) for penetration followed by fragmentation and blast to be used in fire for effect. This shell fuze combination should not be used in area neutralization fire. CP Fuze Nomenclature: M78 Series.