USA will have weapon that kills by pressure wave. Understand

Unlike traditional grenades, which work by expelling metallic shrapnel in all directions, the M111 kills through a wave of pressure – technically called a blast overpressure. When it explodes, the grenade’s plastic casing completely vaporizes, releasing a shock wave that propagates throughout the environment without being blocked by walls, furniture or other internal obstacles. According to the American Army, this wave compresses and decompresses the body’s tissues violently, which can rupture the lungs, eardrums and eyes, and cause damage to the brain.

The main advantage of the new weapon is precisely in urban combat. In war situations inside buildings – such as cleaning rooms and corridors – conventional fragmentation grenades present a serious problem: the shrapnel can, ricocheting off concrete or metal walls, hit allied soldiers themselves. This risk, known militarily as fratricide, was frequently documented during house-to-house combat operations in Iraq.

The M111 replaces the MK3A2, a concussion grenade removed from service in the 1970s because its body was made with asbestos, a carcinogenic material. According to the Army, the new model eliminates this problem: the plastic that forms the casing disappears completely in the explosion, without leaving toxic residue.

The grenade in use until then, the M67 – a weapon the size of a baseball, adopted in 1968 – will not be retired. According to the Army, it will continue to be used in the open field, where shrapnel is more effective. This grenade works by fragmentation: when it explodes, its steel body breaks into shrapnel that disperses in all directions at high speed, with a lethal radius of 5 meters and the ability to hit targets up to 230 meters away.

The M111 then enters the arsenal as a complement, specifically intended for closed environments and combat situations in restricted spaces.

Development of the new weapon was conducted at Picatinny Arsenal, in partnership with the Army Combat Development Capabilities Command’s Armaments Center. To ease the transition, the M111 was designed to share the same five-step armament process as the M67, which reduces the need for retraining.