A munition, such as a warhead, includes a penetrator casing for penetrating hard targets, such as a fortification or reinforced building or other structure. The penetrator casing has a relatively thick nose, and a relatively thin aft section extending back from the nose. A cable interface is in the aft section, and an electrical harness extends from the cable interface, external of the casing, and forward to a nose kit. The penetrator casing may have reduced-thickness portions, to provide weakness points to the casing that facilitate the casing being transformed into fragments of a semi-controlled and desirable size when an explosive within the casing is detonated after the penetration occurs, thus enhancing the effectiveness of the munition.