The current M240 is a slightly modified version of the FN-MAG , which is derived from the FN Model-D BAR, which is a modified version of the Ye Olde BAR designed right at the end of World War 1 by His Royal Highness of Gun Design, John Moses Browning hisself.
Interesting that two of the action types he designed, the M2 and the BAR are still being used as standard issue over a century after they were taken from the drafting desk and put into production.
In my experience the M240 beats all other man portable medium caliber belt fed mgs hands down in reliability and accuracy. In the decades I worked on, and shot them, I never had one fail on me or have to code one out due to simple wear. And as long as my guys didn’t treat it like it was one of their Mini-guns, or try some half-baked idea on dry lubrication because they didn’t like having to clean them everyday in the desert, it would always work when they needed it to.