Take a look at the LMGs from Heckler & Koch in this episode of the The Firearm Blog TV... "In this episode of TFBTV, James looks at Heckler & Koch's light machine guns and general purpose machine guns. The story starts with the HK21, a selective fire roller-delayed blowback-operated firearm. The HK21 was a .308 belt fed machine gun introduced in 1961 and was based on the HK91 or the G3. Accordingly, the HK21 uses a modified G3 receiver. It even has 50% parts interchangeability with the popular HK91 series of rifles. HK subsequently designed several variants. Like other HK rifles, these variants used 2 digit model numbers, and the first digit determined the type of gun, while the second digit determined the caliber. H&K made variants that were belt fed, magazine fed, and in light to medium calibers. In spite of the fact that these were extremely lightweight, accurate, and reliable weapons, they never quite took off to a large degree in many larger NATO countries. James discusses this rare but effective series of light and general purposes machine guns which have found a new life in today's video games."