FN Herstal modernizes the iconic MAG machine gun

FN Herstal unveiled a modernized variant of the FN MAG general-purpose machine gun, introducing a Long Rail Conversion Kit that brings integrated day, night, and thermal optic capability to one of the most widely fielded belt-fed weapons in military history. The update, announced from the company’s headquarters in Herstal, Belgium, targets the growing gap between the optical systems now standard on infantry rifles and the comparatively bare mounting options that have defined most general-purpose machine guns for decades.

Designed in the 1950s by Ernest Vervier at Fabrique Nationale, the weapon fires the 7.62x51mm NATO cartridge from an open bolt using a gas-operated, falling-block mechanism that has proven itself in virtually every climate and terrain type on earth. The gun is currently in service with 90 nations, and hundreds of thousands of units have been produced, making it one of the most widely adopted weapons in the history of modern warfare. The United States military fields it as the M240, where it serves as the primary coaxial and ground-mounted medium machine gun for Army and Marine Corps infantry units. British forces operate it as the L7A2. In both cases and across dozens of other national designations, the mechanical core is essentially the same weapon that rolled out of Liège in the late 1950s, which is simultaneously a testament to the design’s excellence and an honest acknowledgment of how much the surrounding technology has changed.

The new Tactical variant with Long Rail addresses that gap through an 11-inch monolithic Picatinny-pattern top rail that provides approximately 14 inches of usable mounting space for optics, enough to accommodate full-size in-line day sights, night vision devices, and thermal imagers without requiring the shooter to remove and reinstall equipment between missions or lighting conditions. The rail design preserves the original iron sights, meaning a soldier whose optic fails or is damaged does not lose the ability to engage targets. That redundancy matters in sustained combat operations, where equipment takes punishment that no laboratory test fully replicates.

The feed cover now incorporates FN’s AUTO-LOCK retention system, which holds the cover open during loading, unloading, and malfunction clearing without requiring the gunner to use a free hand to keep it raised. The cover stops at 62 degrees and can retain optics weighing up to 2.5 kilograms in that position, protecting glass and electronics from the kind of impact that a falling cover would otherwise deliver. The cover latch itself uses FN’s SIDE-CLICK system, allowing it to be operated from either side of the weapon, a meaningful ergonomic improvement for gunners working in confined vehicle positions or unusual firing stances.

The buttstock brings the same logic of practical modernization to the rear of the weapon, with a three-position length adjustment and a six-position cheek rest that allow the gun to fit a wider range of shooter builds and body armor configurations, a practical consideration given that modern plate carriers and chest rigs change the effective length of pull considerably compared to a base uniform. The stock also incorporates a folding shoulder rest and a soft butt plate and remains fully compatible with the original FN MAG operating system without requiring any modification to the receiver or internal components, meaning the upgrade does not require a new weapon, only new furniture and a new feed cover assembly.

The conversion kit is designed specifically to allow in-service weapons to be updated in the field. Local armourers and technicians can complete the conversion using basic tools, and FN offers the kit as a standalone purchase separate from new weapon orders. The tactical buttstock is also available individually for units that want the ergonomic improvement without the full rail package. For the 90 nations currently operating the MAG in its various configurations, that flexibility significantly lowers the barrier to adoption compared to a wholesale fleet replacement.

Christophe Soleil, FN Herstal’s vice president for small arms, addressed the significance of the update directly: “The new FN MAG TACTICAL with Long Rail GPMG stands as the definitive choice for military organisations seeking decades of proven reliability alongside modern ergonomics and in-line optic capability. These developments, supported by three pending patents, offer our global customers a unique technology that truly marks the difference on the battlefield.”

Soleil added in a separate statement: “While maintaining the weapon’s original performance, this fully qualified configuration is supported entirely by FN. As the original designer and manufacturer, we have evolved the FN MAG to meet modern combat requirements, backed by over 135 years of innovation and industrial excellence.”

The technical specifications of the updated weapon remain unchanged from the standard MAG. The weapon weighs approximately 13.3 kilograms with the barrel assembly adding another 3.3 kilograms. Length runs from approximately 1,175 millimeters with the buttstock fully retracted to 1,245 millimeters fully extended. The rate of fire sits between 650 and 1,000 rounds per minute, fed by belt from a 50-round pouch in the standard configuration. Those numbers place it comfortably within the envelope of comparable NATO general-purpose machine guns, and the Tactical variant does nothing to alter the ballistic performance that has made the platform a standard for allied interoperability.

The FN MAG Tactical with Long Rail will make its public exhibition debut at Eurosatory in Paris from June 15 to 19, where FN Herstal will have the opportunity to put the upgraded weapon in front of procurement officials from across the alliance. European defense budgets are expanding rapidly, and the combination of an established, trusted platform with modern optic integration capability positions the Tactical variant as a lower-risk modernization path than a new-weapon procurement for governments that need to improve capability quickly without retraining entire machine gun crews from scratch. The FN MAG has survived every attempt to replace it for sixty years. This update is FN’s argument that it can survive the next sixty as well.