Warheads
The HE (high explosive) warhead is a general-purpose explosive warhead for use against soft targets such as infantry, unarmored vehicles and fixed positions. The HE warhead detonates on impact or when the fuse runs out; usually the fuse is set to the maximum burn of the rocket motor but it can be shortened for improvised anti aircraft purposes. The warhead case and charge generate a moderate amount of fragmentation, which can pass through many obstacles without stopping.
The HEAT (high explosive anti-tank) round is a standard shaped charge warhead, similar in concept to those used in tank cannon rounds. In this type of warhead, the shape of the explosive material within the warhead focuses the explosive energy on a copper (or similar metal) lining. This heats the metal lining and propels some of it forward at a very high velocity in a highly plastic state. The resulting narrow jet of metal can defeat armor several hundred milimeters of RHA equivalent, such as that used in light and medium armored vehicles. However, heavily armored vehicles such as main battle tanks are generally too well armored to be penetrated by an RPG, unless weaker sections of the armor are exploited. Various warheads are also capable of causing secondary damage to vulnerable systems (especially sights, tracks, rear and roof of turrets) and other soft targets.
Specialized warheads are available for illumination, smoke, tear gas, and white phosphorus. Russia, China, and many former Warsaw Pact nations have also developed a fuel-air explosive (thermobaric) warhead. Another recent development is a tandem HEAT warhead capable of penetrating reactive armor.
So-called PRIGs (Propelled Recoilless Improvised Grenade) were improvised warheads used by the Provisional IRA.
Read more about this topic: Rocket-propelled Grenade