Dual-Purpose Improved Conventional Munitions

The US Army-developed M80 Dual-Purpose Improved Conventional Munition (DPICM) incorporates a shaped charge and an enhanced fragmentation case for use against material and personnel targets.

The Cluster Munitions Policy Memo (19 June 2008) directed that after 2018, cluster munitions must not produce >1% UXO; a limit that will not be waived. It provided no differentiation between types of UXO (hazardous or non-hazardous duds). All cluster munition stocks that exceed operational planning requirements will be removed from the inventory as soon as possible, but not later than June 2009. The previous UXO Requirement: < 2% 20-60km; < 4% < 20km and > 60km. GMLRS DPICM with Self Destruct Fuze (SDF) development and performance demonstrated "hazardous" dud rate of only 0.15%, overall UXO 3.7%, which does not comply with the new DOD Policy.

Each MLRS warhead contains 644 M77 Dual Purpose Improved Conventional Munitions (DPICM) bomblets. The armed M77 submunitions detonate on impact. The antimateriel capability is provided through a shaped charge with a built-in standoff. The M77 can penetrate up to four inches of armor. Its steel case fragments and produces antipersonnel effects with a radius of 4 m.

Called "Steel Rain" by soldiers in the Gulf War, the M77 grenades are dispensed in mid-air above the target, drag-ribbon stabilized, and armed during free fall. Each warhead will saturate a target 200 meters in diameter, combining shaped-charge penetration and blast fragmentation.

DPICM has a significant submunition dud rate (2 to 5 percent depending on terrain), and that can slow free movement through an area into which DPICM has been fired.

In 1995 the Modified (MOD) Dual Purpose Improved Conventional Munitions (DPICM) Advanced Concept Technical Demonstration (ACTD) was initiated after the US Army identified a need to delay and disrupt multiple rocket launcher movement. A variant of the XM85 Self Destruct grenade carried by the ER-MLRS rocket, the MOD DPICM had its firing pin removed to keep the grenade from exploding on contact. The MOD DPICM incorporated a modified integrated chip providing a longer random delay in self destruct and an anti-disturbance sensor to prevent tampering or neutralization. A two-phase test program was developed.

Dual-purpose improved conventional munitions are base-ejection (155 mm only), payload-carrying projectiles. These projectiles are fired with M577 MT fuzes and are filled with 88 dual-purpose grenades. During flight, the base of the projectile is blown off and centrlfugal force disperses the grenades radially from the projectile line of flight.

The 155-mm DPICM projectile contains two types of dual-purpose grenades (64 M42 and 24 M46). Both types are capable of penetrating more than 2.5 inches of rolled homogeneous armor. They are also capable of fragmentation for incapacitating personnel. The M577 MT fuze is preset to function over the target area and initiate the expulsion charge. The expulsion charge pushes the grenades out of the container and onto the target area. The projectile can be modified for the SR mode. The SR mode causes the round to point detonate so as to be visible to the observer and destroy the submunitions. It also may produce an airburst for high-burst registrations.

During the period of May 1994 - May 1996, M864 and M483 Dual Purpose Improved Conventional Munitions (DPICM) were thermally tested by the Mechanical Engineering Research Center within the Department of Civil and Mechanical Engineering at the United States Military Academy. The tests were conducted to support the development of the rapid firing Crusader Artillery System. The tests were to determine (1) if the RDX explosive in the grenades exceeded the melting temperature of 400F° in a hot 155mm gun barrel at up to 650F° and if it did, (2) how long it took for the RDX to reach this temperature.

The use of dud-producing munitions such as DPICM during Operation Iraqi Freedom in early 2003 incurred a penalty, restricting Marine'sr maneuver and follow-on operations in areas after their use. Marines were killed or seriously injured after encounters with dud munitions. After combat operations ceased, the duds continued to be a danger during civil-military operations, both to Marines and civilians. The use of dud producing munitions must be carefully considered in light of the penalty that will have to be paid later. The use of DPICM needs to be carefully considered in its employment. A better round needs to be developed that does not have a 2-4% dud rate.