Well as you say SharonAnne you haven't been there, and a lot has changed since VietNam anyway. I also have not been to the sandbox as they call it, but have used the pistol, revolver, shotgun, and AR15 in anger of one sort or the other in a 20 year law enforcement career mostly tactical.
My sons both grew up in this environment and worked at the ranges as gofers for me, as I have been a tactical instructor since 1977, but am now retired.
To get to the gest of this post, my youngest son, by the time he was 16 yoa, has fired everything used by most police agencies short of a grenade launcher (shoulder fired) which we used to deliver gas.
He is a Combat VETERAN SGT. in the 82nd Airborne, and HAS BEEN THERE AND DUN THAT. Twice in Iraq, and once in Afghanistan. He and his crew fought house to house in Baghdad and that ATROCITY M4 you referred too was a much trusted weapon.
The evidence speaks for itself, and though there are many opinions from various folks the ones that have actually had the experience are the ones I listen to.
Being sniper trained, I cannot imagine taking a 300m head shot other than for entertainment purposes. A good solid torso hit being more desirable and practical at that range, and an M14 WILL buck the distance, and deliver more punch at that range. That SharonAnne is a FACT!
I see that you have lots of strong opinions here and I respect that, but if you don't read magazines as you say you don't you must be getting you opinion from somewhere. So where?
As far as Camp Perry being the real world? Camp Perry is a world of range finders, wind meters, bench rests, shooting vests, custom tailored loads, shooting GLOVES, tuned rifles, and millions of dollars of research. That is what Camp Perry is. A DISPLAY OF THE "LATEST" TECHNOLOGY "NOT AVAILABE" to most, including the combat soldier.