Grendel as a Universal Infantry Cartridge

[stanc]

Here;s the video comparison between 5.56 and the Grendel in similar configurations, and CQM shooting stances for close-range work:

Maybe the 5.56 is a little more manageable. I need to throw the red dot on the Grendel and work with it some more, but an untrained soldier would have an easier time controlling the 5.56 I think.

Those demonstrations show a noticeable difference between the two calibers. In the CQM drill, it took twice as long to fire 7 shots with 6.5 Grendel compared to 5.56 in the same exercise.

However, it was ~1 second for 5.56 vs ~2 seconds for 6.5 -- is that small amount of time likely to matter very much in combat?

P.S. First there was CQB, then came CQC, now there's a CQM? "B" is for Battle, and I think "C" is for Combat, but I haven't a clue as to what "M" stands for?