Unlike standard armor-piercing rounds, a HEAT warhead's penetration performance is unaffected by the projectile's velocity, allowing them to be fired by lower-powered weapons that generate less recoil.

Shaped charge warheads were promoted internationally by the Swiss inventor Henry Mohaupt, who exhibited the weapon before World War II.

Concurrent development by the German inventors’ group of Cranz, Schardin, and Thomanek led to the first documented use of shaped charges in warfare, during the successful assault on the fortress of Eben Emael on 10 May 1940.

Claims for priority of invention are difficult to resolve due to subsequent historic interpretations, secrecy, espionage, and international commercial interest.

Simple fins gave it stability in the air and, provided the grenade hit the target at the proper angle of 90 degrees, the charge would be effective.

In mid-1941, Germany started the production of HEAT rifle-grenades, first issued to paratroopers and, by 1942, to the regular army units (Gewehr-Panzergranate 40, 46 and 61), but, just as did the British, soon turned to integrated warhead-delivery systems: In 1943, the Püppchen, Panzerschreck and Panzerfaust were introduced.

These so-called Schwere Hohlladung (heavy shaped charge) warheads were intended for use against heavily armored battleships.

68 AT rifle grenade was proving to be too light to deal significant damage, resulting in it rarely being used in action.

The need for a large bore made HEAT rounds relatively ineffective in existing small-caliber anti-tank guns of the era.

Germany worked around this with the Stielgranate 41, introducing a round that was placed over the end on the outside of otherwise obsolete 37 millimetres (1.5 in) anti-tank guns to produce a medium-range low-velocity weapon.

The Germans were again the ones to produce the most capable gun-fired HEAT rounds, using a driving band on bearings to allow it to fly unspun from their existing rifled tank guns.

One infantryman could effectively destroy any existing tank with a handheld weapon, thereby dramatically altering the nature of mobile operations.

Since then, the penetration of HEAT rounds relative to projectile diameters has steadily increased as a result of improved liner material and metal jet performance.

This became a challenge for weapon designers: for a long time, spinning a shell was the most standard method to obtain good accuracy, as with any rifled gun.

[13] This affects combat on the open battlefield with long lines of sight; the same T-62 could expect a 70% first-round hit probability using HEAT rounds on target at 500 meters.

It is well suited for use in the attack of other less heavily armored fighting vehicles (AFVs) and for breaching material targets (buildings, bunkers, bridge supports, etc.).

These are HEAT rounds that are effective against older tanks and light armored vehicles but have improved fragmentation, blast and fuzing.

This gives the projectiles an overall reasonable light armor and anti-personnel and material effect so that they can be used in place of conventional high-explosive rounds against infantry and other battlefield targets.

This effect is reduced by the higher first round hit rate of the Abrams with its improved fire control system compared to that of the M60.

[15] The reason for the ineffectiveness of HEAT munitions against modern main battle tanks can be attributed in part to the use of new types of armor.

Reactive armor attempts to defeat this with an outward directed explosion under the impact point, causing the jet to deform and so greatly reducing penetrating power.

[citation needed] The first example of this was the use of the Nord SS.11 ATGM on the Aérospatiale Alouette II helicopter by the French Armed Forces.

[citation needed] On 13 April 1972—during the Vietnam War—Americans Major Larry McKay, Captain Bill Causey, First Lieutenant Steve Shields, and Chief Warrant Officer Barry McIntyre became the first helicopter crew to destroy enemy armor in combat.

A flight of two AH-1 Cobra helicopters, dispatched from Battery F, 79th Artillery, 1st Cavalry Division, were armed with the newly developed M247 70 millimeter (2.8 in) HEAT rockets, which were yet untested in the theatre of war.