One of the lessons learn’t during the recent wars in the Middle East is that the 7.62x51mm owns the long distance engagement. The problem with 7.62mm weapons is that they are heavy. The new HK121 is a next-generation GPMG that is designed to be as light weight as possible.
The HK121 is still a prototype. The Visier magazine article (cover pictured above) states that it is a new design despite the external similarities it shares the the MG4. It weights just a few pounds more than the MG4 making it much lighter than the FN MAG / M240.
[Hat Tip: Max Popenker]