The M72 LAW (Light Anti-Tank Weapon, also referred to as the Light Anti-Armor Weapon or LAW as well as LAWS: Light Anti-Armor Weapons System) is a portable one-shot 66-mm unguided anti-tank weapon. The solid rocket propulsion unit was developed in the newly formed Rohm and Haas research laboratory at Redstone Arsenal in 1959, then the full system was designed by Paul V. Choate, Charles B. Weeks, Frank A. Spinale, et al. at the Hesse-Eastern Division of Norris Thermadore. American production of the weapon began by Hesse-Eastern in 1963, and was terminated by 1983; currently it is produced by Nammo Raufoss AS in Norway and their subsidiary Nammo Talley, Inc. in Arizona.
In early 1963, the M72 LAW was adopted by the U.S. Army and U.S. Marine Corps as their primary individual infantry anti-tank weapon, replacing the M31 HEAT rifle grenade and the M20A1 “Super Bazooka” in the U.S. Army. It was subsequently adopted by the U.S. Air Force to serve in an anti-emplacement/anti-armor role in Air Base Defense duties.
In the early 1980s, the M72 was slated to be replaced by the FGR-17 Viper. However, this program was canceled by Congress and the M136 AT4 was adopted instead. At that time, its nearest equivalents were the Swedish Pskott m/68 (Miniman) and the French SARPAC.
The weapon consists of a rocket within a launcher consisting of two tubes, one inside the other. While closed, the outer assembly serves as a watertight container for the rocket and the percussion-cap firing mechanism that activates the rocket. The outer tube contains the trigger, the arming handle, front and rear sights, and the rear cover. The inner tube contains the channel assembly, which houses the firing pin assembly, including the detent lever. When extended, the inner tube telescopes outward toward the rear, guided by the channel assembly, which rides in an alignment slot in the outer tube’s trigger housing assembly. This causes the detent lever to move under the trigger assembly in the outer tube, both locking the inner tube in the extended position and cocking the weapon. Once armed, the weapon is no longer watertight, even if the launcher is collapsed into its original configuration.
When fired, the striker in the rear tube impacts a primer, which ignites a small amount of powder that “flashes” down a tube to the rear of the rocket and ignites the propellant in the rocket motor. The rocket motor burns completely before leaving the mouth of the launcher, producing gases around 1,400 °F (760 °C). The rocket propels the 66-mm warhead forward without significant recoil. As the warhead emerges from the launcher, six fins spring out from the base of the rocket tube, stabilizing the warhead’s flight. The early LAW warhead, developed from the M31 HEAT rifle grenade warhead, uses a simple, but extremely safe and reliable, piezoelectric fuze system. On impact with the target, the front of the nose section is crushed causing a microsecond electric current to be generated, which detonates a booster charge located in the base of the warhead, which sets off the main warhead charge. The force of the main charge forces the copper liner into a directional particle jet that, in relation to the size of the warhead, is capable of a massive amount of penetration.
A unique mechanical set-back safety on the base of the detonator grounds the circuit until the missile has accelerated out of the tube. The acceleration causes the three disks in the safety mechanism to rotate 90° in succession, ungrounding the circuit; the circuit from the nose to the base of the detonator is then completed when the piezoelectric crystal is crushed on impact.
The M72 LAW was issued as a prepackaged round of ammunition. Improvements to the launcher and differences in the ammunition were differentiated by a single designation. The original M72 warhead penetrated 200mm/8 inches of armor, while the improved M72A2 model boosts this to 300mm/12 inches.
A training variant of the M72 LAW, designated the M190, also exists. This weapon is reloadable and uses the 35-mm M73 training rocket. A subcaliber training device that uses a special tracer cartridge also exists for the M72. A training variant used by the Finnish armed forces fires 7.62-mm tracer rounds.
The US Army tested other 66-mm rockets based on the M54 rocket motor used for the M72. The M74 TPA (Thickened Pyrophoric Agent) had an incendiary warhead filled with TEA (triethylaluminium); this was used in the M202A1 FLASH (FLame Assault SHoulder weapon) 4-tube launcher. The XM96 RCR (Riot Control Rocket) had a CS gas-filled warhead for crowd control and was used with the XM191 quadruple-tube launcher.
Once fired in combat, the launcher is required to be destroyed to prevent its use by the enemy as a booby-trap; the enemy could collapse the launcher to its original configuration, fill it with explosives, and rig it to explode if moved by a soldier believing it to be unused. Due to the single-use nature of the weapon, it was issued as what is called a “wooden round” of ammunition by the Canadian Army and the United States Army, requiring no checks or maintenance, just as small-arms ammunition can be stored in the same manner for years without any problems.
|Designation||Description||US Designation||International Designation|
|M72||66-mm Talley single-shot disposable rocket launcher; pre-loaded with HEAT rocket||M72|
|M72A1||Improved rocket motor||M72A1||L1A1 (UK)|
|M72A2||Improved rocket motor, higher penetration||M72A2||66 KES 75 (Finland)|
|M72A3||M72A2 variant; safety upgrades||M72A3|
|M72A4||Rocket optimized for high penetration; uses improved launcher assembly||M72A4|
|M72A5||M72A3 variant; uses improved launcher assembly||M72A5||66 KES 88 (Finland)|
|M72A6||Warhead modified for lower penetration but increased blast effect; uses improved launcher assembly||M72A6|
|M72A7||M72A6 variant, insensitive-explosive (PBXN-9) version for US Navy||M72A7|
|M72A7 Graze||A7 variant with super-sensitive Graze fuze, restricted from training use (combat-only)||M72A7 w/ Graze|
|M72A9||Blast-optimized HE warhead, DPX-6 explosive||Light Anti-Structure Missile (LASM) [UK]|
|M72E8||M72A7 variant; Fire-From-Enclosure (FFE) capable rocket motor; uses improved launcher assembly|
|M72E9||M72 variant; rocket with improved anti-armor capability; uses improved launcher assembly|
|M72E10||M72 variant; HE-Frag rocket; uses improved launcher assembly|
|M72 EC||Enhanced Capacity, increased anti-armor performance. 315grams PBXW-11 explosive||66 KES 12 (Finland)|
|M72 ASM RC||Reduced-caliber 45mm anti-structure rocket, 0.4kg DPX-6 explosive||66 KES 12 RAK (Finland)|
|M247||2.75″ rocket warhead using M72A2 warhead components, 2.0lb Composition B explosive||M247|
|HAR-66||Turkish variant, mix of A2 and A3 features||HAR-66 (Turkey)|
|M72AS||21-mm reusable trainer||M72AS|
|M190||35mm training variant, fires M73 practice rocket||M190|
|Mass||2.5 kg (5.5 lb) (M72A1-3) / 3.6 kg (8 lb) (M72A4-7)|
|Length||24.8 in (630 mm) (unarmed)
34.67 in (881 mm) (armed)
|Muzzle velocity||145 m/s (475.7 ft/s)|
|Effective firing range||200 m (660 ft)|