Most of the articles I’ve read lately indicate a trend towards larger rounds being preferable to the 5.56 but stopping short of 7.62. US Forces tend to zero in on a preferred round/rifle based upon whatever/wherever the current conflict happens to be. If I’m clearing structures give me an M-4/5.56. If I’m downrange probing Taliban elements an M-16/5.56 is appropriate. If I’m in an urban firefight or sniping I’d prefer the 7.62. Guess that’s why squads are structured with specialty weapons/ammo.But wherever that conflict is it’s difficult to find a more versatile platform than the M-4 chambered in 5.56.
I was out of the Army way before the M-4 was issued and was issued the M-16. We also qualified with the M-14, great platform too!