U.S. Army adopts first new lethal hand grenade since 1968

The United States Army has approved the M111 Offensive Hand Grenade for Full Material Release, clearing the weapon for operational use and marking the first new lethal hand grenade approved for service since 1968.

The decision allows the Army to begin replacing the aging Mk3A2 grenade series, which has remained in limited use due to safety concerns tied to its asbestos body.

The new grenade was developed by the Capabilities Program Executive Office Ammunition and Energetics in cooperation with the United States Army Combat Capabilities Development Command Armaments Center at Picatinny Arsenal. Army officials say the system was designed to address operational lessons learned during urban combat operations in Iraq, where fragmentation grenades sometimes posed risks to friendly forces operating nearby.

Unlike the widely used M67 fragmentation grenade, the M111 relies on blast overpressure rather than fragmentation to neutralize enemy personnel. This design allows soldiers to use the weapon more effectively in enclosed environments such as buildings, tunnels, and confined rooms where fragmentation grenades can produce unpredictable ricochet effects.

“One of the key lessons learned from the door-to-door urban fighting in Iraq was the M67 grenade wasn’t always the right tool for the job. The risk of fratricide on the other side of the wall was too high,” said Col. Vince Morris, Project Manager Close Combat Systems within the Army’s ammunition development program.

“But a grenade utilizing BOP can clear a room of enemy combatants quickly leaving nowhere to hide while ensuring the safety of friendly forces,” Morris said.

Blast overpressure, commonly referred to as BOP, generates a powerful pressure wave when the grenade detonates. In confined spaces this pressure wave can incapacitate or kill personnel without producing large numbers of lethal fragments, reducing the risk of fragments penetrating walls or bouncing unpredictably inside buildings where friendly forces may be operating nearby.

The grenade replaces the Mk3A2 offensive grenade first introduced in 1968. That design used an asbestos body, which led to restrictions on its handling and training use over time. The M111 eliminates this issue by using a plastic body that is fully consumed during detonation, removing the safety concerns associated with asbestos materials.

Army officials say the new design improves both operational readiness and training flexibility. A training version known as the M112 was developed alongside the combat variant, allowing soldiers to practice with equipment that closely mirrors the operational grenade without producing lethal blast effects.

The M111 was also designed to maintain compatibility with existing grenade systems already in service. Soldiers will arm the grenade using the same five-step process used for the M67 fragmentation grenade, allowing troops to transition between grenade types without introducing new training requirements.

“We’ve given our Soldiers and joint warfighters the flexibility to determine in the field which type of grenade will best suit the current situation they are facing, be it open space or confined area,” said Tiffany Cheng, one of the engineers at the DEVCOM Armaments Center who helped develop the M111 system.

Both the M111 and the M112 training grenade use the same fuze components already employed in the M67 fragmentation grenade and its training equivalent, the M69. Army officials say this commonality allows the service to maintain existing production lines while reducing procurement costs.

“By standardizing the arming process and the fuzing, the Army saves taxpayer money without sacrificing lethality on the battlefield,” Morris said. “This is the kind of acquisition reform that is currently underway throughout the Army acquisition enterprise.”

The Army also retains government ownership of the intellectual property associated with the grenade’s design. Officials say this allows multiple manufacturers to compete for production contracts, supporting broader participation across the U.S. defense industrial base.