DSEI 2023: Heckler & Koch introduces new 7.62 mm machine gun

HK421 7.62 mm machine gun, right-hand side. (Janes/Amael Kotlarski)

Heckler & Koch (H&K) debuted its new lightweight 7.62×51 mm chambered machine gun at DSEI 2023 in London.

The new weapon has the HK421 designation and is derived from the company's MG5 series of 7.62 mm general-purpose machine guns (GPMGs). Compared with the MG5A2 – the standard infantry model fitted with a 460 mm-long barrel – the HK421 with its 421 mm-long barrel (the longest currently on offer) is approximately 2.7 kg lighter. The company also offers a 330 mm-long barrel, which gives the weapon an approximate weight of 8.3 kg (9 kg with the ‘para butt-stock'). When fitted with the 421 mm barrel, the HK421 has a maximum overall length of 995 mm and a minimal overall length of 810 mm.

Some key design features of the MG5 series are retained in the HK421, including the long-stroke gas piston system, quick-change barrel, feed mechanism, and feed tray cover with a loaded belt indicator. It also retains the MG5's safety mechanism, which consists of three sear engagement surfaces on the underside of the bolt carrier, as well as a carrier retention latch on the underside of the receiver. This is to prevent an accidental discharge of the weapon should the user release the bolt before it is fully locked to the rear, or if the bolt is released forward if and when the pistol grip module (housing the sear) is removed from the receiver.