Saab launches HEAT 758: a new round to defeat Russian reactive armour

Saab’s new HEAT 758 round, designed for the Carl Gustaf Mk 4, is built to defeat the explosive reactive armour used to protect Russian tanks. With customers already confirmed, the timely launch reflects the drive to increase infantry lethality.

By Sam Cranny-Evans, editor of Calibre Defence, published on May 7, 2026.

Saab Dynamics has launched HEAT 758, a new anti-tank round for the Carl Gustaf, during a live fire demonstration in Sweden. Despite only launching the round on May 7, it already has a customer.

“This round is our response of developments of the battlefield where reactive explosive armour has become a major problem for regular munitions trying to defeat armoured vehicles,” Michael Höglund, head of Saab’s business unit Ground Combat said on May 5.

Like its predecessor, the HEAT 751, the new round uses a tandem high explosive anti-tank (HEAT) warhead, designed specifically to defeat Russian explosive reactive armour (ERA). According to a Saab representative who presented during the event, the round has been developed using machine learning tools and extensive testing.

“We used machine learning to run through 50,000 designs of precursor models to make it work across all of the Russian types of ERA,” he explained. This includes:

• Kontakt-1, the oldest and lightest form of Russian ERA, designed to counter HEAT warheads.
• Kontakt-5, a late Cold War design that introduced modules with heavier plates to counter HEAT and tank rounds.
• Relikt, Russia’s newest ERA found on its T-90M. It provides the greatest level of protection of the three.

Once the machine learning had developed several plausible precursor options, the team then built prototype rounds for testing. Saab Dynamics has since fired at least 500 rounds in the development of the HEAT 758, the representative said.

Specifications: HEAT 758

The HEAT 758 round is an 84 mm round with a tandem HEAT warhead using a copper liner. It can penetrate up to 700 mm of armour behind ERA, the company said. For comparison, the HEAT 751 could penetrate around 500 mm. The new round provides a range up to 600 m using rocket motor assistance to reach the target. It also uses the Saab Firebolt technology, which automatically populates key information like propellant temperature into the Carl Gustaf fire control system. This data is then used to provide a firing solution. During the live firing demonstration, the round was fired out to 500 m against a salvaged Soviet tank hull.

Tech explainer: What is a non-initiating precursor?

The HEAT 758’s precursor charge is described by Saab as “non-initiating,” which means it is designed to avoid reliably triggering the ERA. To explain how this works, it is beneficial to start with a short explanation of ERA and how that type of armour works.

Put very simply, two armoured steel plates are used to sandwich a layer of explosive. Ideally, those plates are arranged at an angle within an external box. For a system like Kontakt-5, which is used to protect T-72B3 tanks, there will be two sandwiches in each box. When a high velocity projectile strikes the ERA, it penetrates the first armoured plate and hits the explosive insert. The projectile – be that a HEAT jet or kinetic energy round fired by a tank – creates a shock that crosses the explosive’s initiation threshold.

That detonation throws the plates, one travelling towards the threat and one away from it. As the plates are at an angle, they constantly move new material into the projectile’s path, eroding it. The difference in pressure created can also disrupt the jet of a HEAT warhead, breaking it into smaller pieces that can be absorbed by the vehicle’s armour.

The non-initiating precursor

So, a non-initiating precursor is often a small HEAT warhead that penetrates the plate but at a lower energy. The lower level of energy enables the precursor warhead to degrade the explosive layer or pre-detonate it. This reflects a careful balancing act; the precursor needs to be powerful enough to get through several armoured plates in the case of some Kontakt-5 modules. But not so powerful that it triggers the explosive sandwiches that make the armour work.

A few milliseconds after the precursor has detonated, the main charge with its much larger warhead detonates. Broadly speaking, it will encounter one of two scenarios: In the first, the precursor will have degraded the explosive element, allowing the much larger charge to act on the remainder of the ERA module and the main armour of the tank. The tank’s hull is typically a few hundred millimetres thick and may include further advanced arrays. Furthermore, the turret cheeks of the T-72B, which is often the base for the T-72B3, may include non-reactive spaced armour arrays. This type of passive armour is also very effective at reducing HEAT penetration. However, the 700 mm behind ERA capability of the HEAT 758, which may depend on the type of ERA, should be sufficient to do the job.

The second scenario is that the precursor will have initiated the plates. This means they will be moving or will have finished moving when the main charge initiates. As a result, more of the jet should reach the armour in one piece, increasing its penetration and behind armour effects. Saab did not reveal how the HEAT 758 precursor works, but the above hopefully helps clarify some of the physics that are involved.

Calibre comment: HEAT 758 and platoon lethality

One Saab representative explained that a Carl Gustaf is used at the platoon level, while the disposable AT-4 is for the section level. The reloadable weapon can fire several munition types including anti-structure rounds, and programmable high explosive rounds. These natures were demonstrated by Saab during the media visit. The anti-structure round was used with variable fuzing, penetrating a concrete wall and detonating inside a room in one scenario. The programmable high explosive rounds were detonated over a body of water, creating a dense pattern of fragmentation on the ground.

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These rounds are quite well known to most users of the Carl Gustaf, but the HEAT 758 is designed to increase platoon lethality. With its ability to reduce the efficacy of Russian ERA, the round gives platoons the lethality to engage tanks with a good chance of success. This is because, if the HEAT 758 round penetrates a tank’s armour, it would likely have considerable behind armour effects. Even with a single hit. So, its addition to a platoon should help increase infantry lethality, reducing their reliance upon other assets during combat.

The lead image shows personnel loading a HEAT 758 round into a Carl Gustaf launcher. Credit: Saab.