Heckler & Koch has introduced its latest innovation in the field of military firearms, the HK421 7.62 mm lightweight machine gun on display at Eurosatory 2024. This new weapon evolves from the company’s renowned MG5 series of 7.62 mm general-purpose machine guns (GPMGs). One of the most significant upgrades in the HK421 is its weight reduction. Compared to the standard infantry MG5A2, which features a 460 mm-long barrel, the HK421’s 421 mm-long barrel (the longest currently offered) makes it approximately 2.7 kg lighter. This weight reduction enhances the mobility and ease of handling for infantry units. Additionally, the company provides a 330 mm-long barrel option, bringing the weapon’s weight down to approximately 8.3 kg (9 kg with the ‘para butt-stock’). When equipped with the 421 mm barrel, the HK421 boasts a maximum overall length of 995 mm and a minimal overall length of 810 mm.
The HK421 retains several key design features from the MG5 series, including the long-stroke gas piston system, quick-change barrel, feed mechanism, and feed tray cover with a loaded belt indicator. The robust safety mechanism from the MG5 is also present, featuring three sear engagement surfaces on the underside of the bolt carrier and a carrier retention latch on the underside of the receiver. This system prevents accidental discharges by ensuring the bolt is fully locked to the rear before firing or if the pistol grip module is removed from the receiver. In addition to its structural enhancements, the HK421 incorporates a hydraulic buffer, allowing compatibility with various buttstocks, such as the collapsible MP7 stock and the HK416A8 buttstock.
The HK421 is available with two barrel length options: 13 inches (weighing 8.3 kg) and 16.5 inches (weighing 8.5 kg). It features a 3-position gas block for normal operations, sustained fire, and suppressed fire. Importantly, it can be set on safe in any loaded state, adding an extra layer of safety for operators. The handguard module is detachable, revealing a Picatinny rail for accessories, enhancing the weapon’s versatility. Heckler & Koch has showcased the HK421 on social media, featuring the weapon in a Flat Dark Earth (FDE) finish. A Sniper Grey version is also advertised, catering to different operational preferences and environments.
Heckler & Koch GmbH (HK or H&K) is a German firearms manufacturer that produces handguns, rifles, submachine guns, and grenade launchers. The company is located in Oberndorf am Neckar, Baden-Württemberg, and also has subsidiaries in the United Kingdom, France, and the United States. The company initially produced machine tool and metal parts until 1956 when, in response to a Bundeswehr contract for a new service rifle, HK developed the Heckler & Koch G3. The success of the G3 rifle prompted HK to transition to the defense industry. HK was briefly owned by Royal Ordnance from 1991 to 2002, and is currently part of the Heckler & Koch Group, comprising Heckler & Koch GmbH, Heckler & Koch Defense, NSAF Ltd., and Heckler & Koch France SAS. The company’s motto is “Keine Kompromisse!” (No Compromises!).
