Editing Rocket-propelled grenade (section)

==Design==
[[File:Obus 501556 fh000021.jpg|thumb|Sectioned [[high-explosive anti-tank]] round with the inner shaped charge visible]]
[[File:CumulativeHead.png|thumb|right|A diagram of a high-explosive anti-tank (HEAT) warhead of an RPG rocket (the propellant section is not shown) 1: Aerodynamic cover; 2: Air-filled cavity; 3: Conical liner; 4: Detonator; 5: Explosive; 6: [[Piezoelectric sensor|Piezo-electric]] trigger]]

The RPG warhead being used against tanks and other armor often has a [[shaped charge]] explosive warhead. A shaped charge is an [[explosive]] charge shaped to focus the effect of the explosive's energy. Various types are used to penetrate tank armor; typical modern lined shaped charge can penetrate steel armor{{clarify|date=December 2013}} to a depth of seven or more times the diameter of the charge (charge diameters, CD), though greater depths of 10 CD and above<ref name="llnl"/> have been achieved. Despite the popular misconception that shaped charges "melt" tank armor, the shaped charge does not depend in any way on heating or melting for its effectiveness; that is, the [[superplastic]] metal jet from a shaped charge impact on armor forms mainly due to a sudden and intense [[stress (mechanics)|mechanical stress]] and does not melt its way through armor, as its effect is purely due to kinetic energy in nature.

An RPG comprises two main parts: the launcher and a rocket equipped with a warhead that follows a ballistic trajectory after the rocket motor has completed its burn. The most common types of warheads are [[high explosive]] (HE) and [[high-explosive anti-tank]] (HEAT) rounds. HE rounds can be used against troops or unarmored structures or vehicles. HEAT rounds can be used against armored vehicles. These warheads are affixed to a [[rocket motor]] and stabilized in flight with fins. Some types of RPG are single-use disposable units, such as the [[RPG-22]] and [[M72 LAW]]; with these units, once the rocket is fired, the entire launcher is disposed of. Others are reloadable, such as the [[Soviet Union|Soviet]] [[RPG-7]] and the Israeli [[B-300]]. With reloadable RPGs, a new rocket can be inserted into the muzzle of the weapon after firing.

An issue that affected the earliest RPG weapon systems such as the German [[Panzerschreck]] was that rocket motor propellant could harm the operator. The weapon therefore featured a metal shield attached to the launch tube to protect the operator’s face from the blast. With later designs such as the RPG-7, the rocket exits the launcher with a low-powered [[gunpowder]] charge, and the main rocket motor then fires after the rocket has travelled {{convert|10|m|abbr=on}}. In some other designs, the propellant charge burns completely within the tube.

An RPG is an inexpensive way for an infantryman to safely deliver an explosive payload or warhead over a short distance with reasonable accuracy. Substantially more expensive guided [[anti-tank missile]]s are used at larger distances when accuracy or an overfly top attack are paramount. Anti-tank missiles such as the [[AT-3 Sagger|Malyutka]] can be guided by the operator after firing by sight, heat sensors or IR signatures; an RPG however is not guided towards the target. Nor can RPG rockets be controlled in flight after being aimed and launched. While the lack of active targeting technologies or after-firing guidance input can be viewed as a weakness, it also makes RPGs cheap and hard to defend against with electronic countermeasures or decoying. For example, if a soldier or other fighter launches an RPG at a hovering helicopter, even if the helicopter releases flares to confuse optical seekers, chaff to confuse radar, or engages in signal jamming, these will have no effect on an in-flight RPG warhead, even though these measures might protect against more sophisticated surface-to-air missiles.

===Warheads===
[[File:Krtsanisi National Training Center, Georgia (5).jpg|thumb|left|[[Georgia (country)|Georgian]] soldiers prepare to fire a RPG]]
[[File:Rebel in northern Central African Republic 04.jpg|thumb|right|A rebel in the northern [[Central African Republic]] holding a loaded RPG]]
[[File:ASC Leiden - Coutinho Collection - 19 11 - Manten military base in the liberated areas, Guinea-Bissau - 1974.tif|thumb|Guerilla of the [[African Party for the Independence of Guinea and Cape Verde|PAIGC]] resistance movement against Portugal holding an RPG in [[Guinea-Bissau]], 1974]]

The HEAT ([[high-explosive anti-tank]]) round is a standard shaped charge warhead {{Citation Needed|date=March 2025}}, similar in concept to those used in many<!--the major tank developing countries also use fin-stabilized APDS from their smoothbore guns, while the british use HESH and spin-stabilized APDS from their rifle guns.--> 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 equivalent to several hundred millimeters of RHA, 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. The 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 [[Battle of Mogadishu (1993)|improvised anti aircraft]] purposes.<ref name="maritimesecurity"/>

Specialized warheads are available for illumination, smoke, tear gas, and white phosphorus. Russia, China, and many former Warsaw Pact nations have also developed a [[thermobaric weapon|fuel-air explosive]] (thermobaric) warhead. Another recent development is a tandem HEAT warhead<ref name="strategypage"/> capable of penetrating [[reactive armor]].

So-called PRIGs (propelled recoilless improvised grenade) were improvised warheads used by the [[Provisional IRA]].

===Effectiveness===
The [[RPG-29]] uses a [[tandem-charge]] [[high-explosive anti-tank]] warhead to penetrate [[explosive reactive armor]] (ERA) as well as composite armor behind it.

In August 2006, in [[al-Amarah]], in Iraq, a Soviet RPG-29 damaged the front underside of a Challenger 2 tank, detonating ERA in the area of the driver's cabin. The driver lost part of a foot and two more of the crew were injured, but the driver was able to reverse {{convert|2.4|km|abbr=on}} to an aid post. The incident was not made public until May 2007; in response to accusations, the MoD said "We have never claimed that the Challenger 2 is impenetrable." Since then, the ERA has been replaced with a [[Chobham armour|Dorchester block]] and the steel underbelly lined with armor, as part of the 'Streetfighter' upgrade, which was a direct response to this incident.<ref name="Rayment"/> In May 2008, ''[[The New York Times]]'' disclosed that an American M1 tank had also been damaged by an RPG-29 in Iraq.<ref name="Gordon"/> The American army is ranking the [[RPG-29]] threat to American armor as high; they have refused to allow the newly formed Iraqi army to buy it, fearing that it would fall into the hands of insurgents.<ref name="Grant"/>

Various armies and manufacturers have developed add-on tank armor and other systems for [[Urban warfare|urban combat]], such as the [[Tank Urban Survival Kit]] (TUSK) for M1 Abrams, [[slat armor]] for the [[Stryker]], ERA kit for the [[FV432 AFV|FV432]], AZUR for [[Leclerc tank|Leclerc]], and others. Similar solutions are [[active protection system]]s (APS), engaging and destroying closing projectiles, such as the Russian [[Drozd]] and [[Arena Active Protection System|Arena]], as well as the recent Israeli [[Trophy Active Protection System]].

The [[RPG-30]] was designed to address the threat of active protection systems on tanks by using a false target to trick the APS.<ref name="ARMS-TASS"/> The RPG-30 shares a close resemblance with the [[RPG-27]] in that it is a man-portable, disposable anti-tank rocket launcher with a single-shot capacity. However, unlike the RPG-27, there is a smaller diameter precursor round in a smaller side barrel tube in addition to the main round in the main tube. This precursor round acts as a false target, tricking the target's active protection system into engaging it, allowing the main round a clear path into the target, while the APS is stuck in the 0.2–0.4 second delay it needs to start its next engagement. Recent German systems were able to reduce reaction delay to mere milliseconds, cancelling this advantage.<ref name="ARMS-TASS"/>

The PG-30 is the main round of the RPG-30. The round is a {{convert|105|mm|abbr=on}} tandem shaped charge with a weight of {{convert|10.3|kg|abbr=on}} and has a range of {{convert|200|m|abbr=on}} and a stated penetration capability in excess of {{convert|600|mm|abbr=on}} [[rolled homogeneous armor]] (RHA) (after ERA), {{convert|1,500|mm|abbr=on}} reinforced concrete, {{convert|2,000|mm|abbr=on}}, and {{convert|3,700|mm|abbr=on}} of soil.<ref name="ARMS-TASS"/> Reactive armor, including explosive reactive armor (ERA), can be defeated with multiple hits into the same place, such as by tandem-charge weapons, which fire two or more shaped charges in rapid succession.

===Protection===
An early method of disabling shaped charges developed during World War II was to apply thin skirt armor or meshwire at a distance around the hull and turret of the tank. The skirt or mesh armor ([[cage armor]]) triggers the RPG on contact and much of the energy that a shaped charge produces dissipates before coming into contact with the main armor of the vehicle.<ref name="stugiii"/> Well-sloped armor also gives some protection because the shaped charge is forced to penetrate a greater amount of armor due to the oblique angle.<ref name="panzerworld"/> The benefits of cage armor are still considered great in modern battlefields in the Middle East,<ref name="defensetech"/> and although similar effects can be obtained using [[spaced armor]], either as a part of the original design or as [[Appliqué armor#Appliqué armour|appliqué armor]] fitted later, cage armor is preferable due to its low weight and ease of repair.

Today, technologically advanced armies have implemented [[composite armor]]s such as [[Chobham armour]], which provide superior protection to steel. For added protection, vehicles may be retrofitted with reactive armor; on impact, reactive tiles explode or deform, disrupting the normal function of the shaped charge. Russian and Israeli vehicles also use active protection systems such as Drozd, Arena APS or Trophy. Such a system detects and shoots down incoming projectiles before they reach the vehicle. As in all arms races, these developments in armor countermeasures have led to the development of RPG rounds designed specifically to defeat them, with methods such as a tandem-charge warhead, which has two shaped charges, of which the first is meant to activate any reactive armor, and the second to penetrate the vehicle.