Staff of Destruction

Light Anti-Tank Weapon or LAW.
The weapon consists of a rocket packed inside of a launcher made up of two tubes, one inside the other. While closed, the outer assembly acts as a watertight container for the rocket and the percussion cap-type 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 igniting 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.[5] 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 micro-second electric current to be generated, which detonates the warhead. The fuse then 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 degrees in succession, ungrounding the circuit; the circuit from the nose to the base of the detonator is then completed when the piezo-electric crystal is crushed on impact.

Ammunition
M72 LAW's rocket M72 demonstration at Fort Benning, Georgia in the 1960s. The M72A2 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 most common M72A2 LAWs came prepacked with a rocket containing a 66 mm HEAT warhead which is attached to the inside of the launcher by the igniter. The standard M72A2 anti-armor HEAT warhead has an official stated penetration in 1977 of up to 20 cm/8 inches of Steal plate, 600mm (2 feet) of reinforced concrete], or 1.8 meters (6 feet) of soil.

Don't stand behind the launcher.

REF
http://en.wikipedia.org/wiki/M72_LAW