On 5 May 2026, at the Bofors Test Center in Karlskoga (Sweden), Saab conducted a live-fire demonstration of the CARL-GUSTAF M4 recoilless rifle before an audience of 150 international guests from 25 countries, officially unveiling the new HEAT 758 anti-tank round.

FW MAG attended the event and a series of briefings on new products and developments from Saab, which we will be covering in the coming days. Among the various rounds fired using different munitions from the CARL-GUSTAF family, the demonstration included the engagement of a T-80 main battle tank at a range of 500 m with the new HEAT 758.

The HEAT 758 was developed in response to the progressive proliferation of Explosive Reactive Armour (ERA) on modern armoured vehicles. ERA consists of explosive bricks mounted externally on the hull or turret: upon impact by a HEAT round, the explosive detonates and projects the metallic cladding plates into the path of the shaped charge jet, degrading or nullifying its penetrating capability before it reaches the main armour.

Soviet and later Russian production developed 3 successive generations of ERA of increasing sophistication: KONTAKT-1 (first generation, 1982, specifically designed to counter shaped HEAT charges), KONTAKT-5 (second generation, 1985, effective also against kinetic energy APFSDS penetrators), and RELIKT (third generation, 2006, featuring a double heavy-plate configuration with approximately twice the protective effectiveness of KONTAKT-5). The widespread proliferation of these protective systems (including the consolidated practice of fitting ERA to light armoured vehicles and infantry fighting vehicles) has made the problem structural for conventional anti-tank munitions.

The solution: tandem warhead with non-initiating precursor

The conventional response to the ERA problem is the tandem warhead: a forward precursor activates and expends the ERA panel before the main charge arrives. However, in traditional tandem configurations, the detonation of the precursor leaves residue in the ballistic path that can interfere with the main charge jet, partially reducing its penetrating effectiveness.

The true innovation of the HEAT 758 lies in the adoption of a Non-Initiating Precursor (NIP), whose precise operating mechanism has not been disclosed, for obvious reasons of intellectual propriety protection. Its functioning can nonetheless be outlined in broad terms: rather than detonating the ERA panel, the NIP physically traverses it without initiating it (likely via a jet of low-density material) perforating the explosive bricks and leaving a clean, residue-free channel. The main charge then finds a clear path and reaches the primary armour at maximum efficiency. The penetration performance declared by Saab is up to 700 mm of RHA-equivalent armour, sufficient to defeat the most heavily protected main battle tanks currently in service.

To optimise the NIP design, Saab employed artificial intelligence and machine learning tools, conducting over 50,000 computer simulations to evaluate as many geometric configurations and design variants, identifying the solution with the best performance against all 3 generations of Russian ERA (KONTAKT-1, KONTAKT-5, and RELIKT), before developing multiple physical prototypes for experimental validation and ultimately arriving at the HEAT 758.

The operational advantage of a precursor effective across all ERA generations is as much tactical as it is technical: the firer is not required to identify the type of reactive protection fitted to the target prior to engagement. The HEAT 758 guarantees penetration regardless of which ERA generation is present on the vehicle, eliminating an uncertainty that in combat can prove decisive.

Integration with the M4 system: FIREBOLT and FCD 558

The HEAT 758 integrates FIREBOLT technology, the bidirectional communication protocol developed by Saab for the CARL-GUSTAF M4. Via FIREBOLT, the round transmits to the Fire Control Device 558 (FCD 558) data on charge type and propellant temperature; the FCD integrates this information with target range, ambient temperature, and atmospheric pressure, and automatically computes the optimal fire solution without manual input from the firer. The process reduces the operator's cognitive load and increases the probability of a first-round hit, a critical parameter in close-combat scenarios.

Positioning within the munitions family and commercial outlook

The HEAT 758 is positioned as the direct successor to the HEAT 751, the previous tandem round in the CARL-GUSTAF family, with penetration in excess of 500 mm RHA and an effective range of 500 m, which it is intended to replace in the product catalogue. Compared to the 751, the 758 increases declared penetration by 200 mm (to 700 mm), extends effective range by 100 m (to 600 m), broadens ERA effectiveness across all generations, adds FIREBOLT compatibility, and is also lighter at 3.7 kg. On the commercial side, Saab has confirmed that an undisclosed customer has already contracted the supply of the HEAT 758 prior to the round's public unveiling.

Stay tuned for more from Karlskoga in the coming days.

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