HK23

Even though the roller-delayed blowback operated HK21 was not adopted into main service by Bundeswehr, Heckler & Koch (HK) did not give up with the G3 derived MG models, they switched the development focus for export instead. Following NATO's interest in 5.56 calibre light machineguns, a step down version of HK21 was produced, the 5.56 calibre HK23. While retains most features from HK21, major changes to HK23 would be the reworked barrel and feeding mechanism to incorporate the smaller 5.56x45mm cartridge, but the mechanism working principle remains the same, the weapon still fires from a closed bolt and able to achieve a 800 rounds per minute cyclic rate of fire. Features retained from HK21 include the ambidextrous fire selector lever, integrated bipod, the quick-detach barrel and the compatibility with HK's proprietary optic clamp mount. Compared to HK21, HK23 is both lighter in weight and smaller in size/dimensions. Just like HK21, the belt feeding module is located beneath the receiver, which meant HK23 was also able to accept box magazines on top of being able to feed from munition belts. HK23 can be fed with 20-/30-round box magazines, 80-round drum magazine or lose/boxed ammo belts in lengths of 50 increments. Close bolt firing meant the weapon have limited the maximum effective range and sustained firepower capabilities when compared to open bolt design MGs, however it does have a more accurate semi-automatic firing performance, to an extend they function relatively ideal as a squad automatic weapon. HK23 is noted for enter the US 5.56 calibre SAW competition as one of the candidates between 1970 and 1980, however the gas-operated FN Minimi won the competition, obtained the M249 SAW designation and entered service with the US military. Despite the failure in the US SAW competition, HK23 did achieve a moderately well sale to other nations. However the production of roller-delayed blowback MGs gradually slowed down with the trending interest in gas-operated MGs, HK ceased the production of HK21 lines of MG completely by early 2000, the new line of MG developed by HK would be the HK123 (MG4) family.