The weapon comes with 3 rotating barrels to reduce overheating and erosion during a firefight.
[1] The RMG 7.62 is a development of the MG3, intended as a vehicle mounted weapon where changing the overheated barrel would be a problem.
Like the MG3, it is a recoil operated weapon that fires at about 800rpm and uses the belt feed from the MG3.
The weapon comes with a cluster of 3 barrels that change over when overheated leaving the previously lined up barrel to cool off.
[1] The RMG 7.62 is not a rotary weapon like a Minigun despite it having the appearance of one externally.