Seems like .300 is the new go-to for suppression. If I wasn't ever gonna use a can, I'd go 6.5cm or 6.8spc. If I was looking for something non-nato that is.
Been mulling this over in my mind also. Im just hesitant to get away from nato rounds for some reason.
Do you mean 6.5 Grendel? The 6.5CM is an AR10 platform. I agree though, the 6.5CM is also a great round, as well as the grendel in the AR15.