My point, which some didn’t get, is that the M16 from the Vietnam era isn’t the same rifle issued today. I also was comparing ammo weight, I have no idea what the amount of ammo carried with an M14 was. 160 rounds of 7.62 will weigh about the same as 350-400 5.56mm. I am young enough to have missed Vietnam, but old enough I went through college with a bunch of vets, and am well aware of the many problems it had originally. The current models are pretty well proven weapons. I appreciate your service as well, I lost a cousin (Army Airborne) in Vietnam, and a nephew in Iraq (Marine), have two brothers in law and a sister in law that are Marines, dad was in the Air Force, another nephew in the Air Force, two brothers and two uncles in law enforcement, so have more than my range time experience regarding current M4’s. The current models are pretty decent weapons, versatile, optics ready and modular as well.
There are many new weapons and calibers that have built on those lessons learned, yet the army (civilians, many of who never served in uniform) at Picatinny, Aberdeen, and Benning stubbornly block any and all new systems - other than that weird and useless 25mm monster.
Having more rounds is a good thing but not everthing. The heavier and lengthier weapon I carried didn't need as many rounds because it was designed for aimed fire, not "spray and pray". And despite all of the silly propaganda by the whiz kids, the 5.56 round doesn't penetrate obstructions well, doesn't buck side winds well and loses energy rapidly as the range increases. Even though 7.62 was more punishing to carry and to fire, I knew that it would always fire - always - and it would hit what I was aiming at and what I hit stayed down.
I was one of those hit in Vietnam and as I was lying there putting on a tourniquet and waiting for my medevac, my lieutenant came crawling up to me and said "Rick, I'm really sorry you're hurt - but can I have your M-14?".
We need a new generation weapon that is more reliable, harder-hitting, precise as a sniper rifle, and utterly impervious to filth, sand, salt water. The Kalashnikov series of weapons are famous for that kind of reliability - can't we do better than an uneducated tank sergeant?
Semper Fi