Military Knowledge: M141 Bunker Defeat Munition

M141 or SMAW-D (“Disposable”), is a single-shot, shoulder-launched weapon designed to defeat hardened structures. The weapon was designed as a modification of the United States Marine Corps Shoulder-launched Multipurpose Assault Weapon (SMAW) to fill the void in the United States Army inventory of a “bunker buster” weapon.

The SMAW-D operates on the principle that the recoil created by launching the rocket is counteracted by a “backblast” of gases fired from the rear of the weapon like RPGs. This makes the SMAW-D inherently dangerous, especially in confined, urban areas, as is with all weapons of this design.

M141 Bunker Defeat Munition has two configurations: a “carry mode” in which the launcher is 810 mm long, and a “ready to fire mode” in which the launcher is extended to its full length of 1,400 mm.

The warhead is the same High Explosive, Dual Purpose (HEDP) as the United States Marine Corps SMAW. It is effective against masonry and concrete bunkers as well as lightly armored vehicles. The projectile is capable of penetrating up to 200 mm of concrete, 300 mm of brick, or 2.1 m of sandbags. The warhead is activated by a crush switch in its nose that is able to distinguish between hard and soft targets. On soft targets, such as sandbags, the detonation is delayed until the projectile is buried in the target, producing a devastating effect. The warhead detonates immediately on contact with hard targets.

M141 Bunker Defeat Munition specifications:
Weight: 1.7 kg
Length: 810 mm
In service (US Army): Since 1999
Caliber: 83.5 mm rockets
Range: 15-1000 meters
Penetration rate in concrete: 200 mm
Penetration rate in brick: 300 mm
Penetration rate in sandbags: 2.1 meters

Source: Wikipedia