Primarily to provide smoke for target marking and incendiary purposes.
This warhead is a ballistic match for high explosive (HE) Warhead M151. The M156 consists of a steel body, a base, and an adapter, brazed together. The body is shaped at the forward end to form the ogive. The base is an extruded steel cup threaded for attachment to the rocket motor. The steel adapter, at the forward end of the warhead, is threaded to receive the fuze. It also serves to retain the burster charge tube.
Collaborative ORDnance data repository (CORD)