Eliminating Full Auto had nothing to do with the Army. It was the Marine Corps Ammunition Branch accessing the negative (in terms of "days of supply," impact of the M249 SAW ammo pack-out on Landing Force Ammo stored aboard amphib shipping known as "L-Form." Needless to say this non-tactical input from the logisticians came out of left field, but played well with senior officers who wanted "to fix" the M16A1, not only its mechanical elements but its perceived operational/training ones as well.

You asked:
"Just how far did this recommendation go? Were any prototype receivers built, tactical and logistical assessments made, etc, as to the impact a fixed semiauto M16 on Army and/or Marine doctrine? Or was the idea to have a sort of M14 approach, issuing rifles that were capable of full auto but had their selectors fixed for SA firing only? Any details you can shed here would be greatly appreciated. It is interesting that a Marine Corp group would stump for SA-only. So was the 3-shot burst a sort of institutional compromise and outgrowth of that goal?

AT that point early in 1980, no prototype rifle contracts were in place. The improved rifle only existed on a series of briefing slides, so there were no prototypes at that time. But the SA only was a serious matter that had already been "decisioned" before I was assigned. The 3-RBC was a compromise I brought to the table, along with the fully adjustable rear sight, MB, etc.. I had found them in test rifles from the early 70's that were stored at Picatinny Arsenal, or I the gun vault at Colt's in Hartford. Also important to your question is that at this early phase, the Marine Corps "at large" (or "the Fleet Marine Force") as we referred to it), only knew of an improvement program, not what it consisted of. So at that point no one was assigned to revise doctrine and tactics.  

Coldblue:

Can you give us a summary, rundown, a list of features, a short description of what would describe what the ARMY's "M16A2" would have looked like had the M16A2 been designed completely "in-house" WITHOUT ANY Marine Corps input?
The short answer would be they would have kept the M16A1 basically as it was. Their logistics command was against the whole USMC program because they had not been assigned or funded to fix any M16A1 deficiencies.  Ft. Benning, the "User" for such Army decisions were not currently funded either, and wosre yet, had no "Requirement". And Picatinny, their material developer, was sitting on their collective hands waiting for "A Requirement Document" and associated funding. That's when the Marines, via the JSSAP program housed at Picatinny, came on the scene with several million $ and an in-place liaison officer to honcho it in the JSSAP office, me.
A bit more objectively: about the only real change that the Army would have made was to adopt their developmental XM777 round to replace the M193. Their XM777 had not won the NATO 5.56 ammo selection testing, like the Belgian SS109 had, but it met the minimum NATO armor penetration requirement and did not require a new barrel or twist like the SS109 did. This would have allowed them to "improve" the rifle on the cheap while they developed their next "future rifle firing darts, new revolutionary weapon/ammo technology, objective individual weapons, bursting munitions weapon, etc...(all failed by the way after million$ squandered...)

"...That's the kind of thing that gave me (and probably a lot of other people) the impression that Ordnance Corps wasn't in any way tuned in to what the Soldier on the ground needed. And more to the point, how hard Ordnance resisted anything "not invented here..."

That is pretty much true. Whatever the current thing was, the "institution" worked more-harder to keep it in place and unchanged. In my opinion, this was deliberate so the aging current system became more and more out of date. Then this had the result of the "User" supporting program funding for what ever wiz-bang was resident on the developer's powerpoint presentations of the decade. The other major weakness is that the "Green Suits" changing every 2 to 3 years allowed the developers to either lay low from knowledgeable military that had been in place for a couple of years and were seeing through the façade, or flim-flaming newbee's with their powerpoint promises of "leap ahead" technology. If you go back to the 50's and 60's you will see one failed program after another that the developers grew fat on, while the troops were left short-changed...

Get an early copy of Jane's Infantry Weapons (1st year of issue is the best) and read the history of series of failed Army programs prior to the AR-15's adoption in 1970. Don't have access to a copy right now, but SPIW, Low Maintenance Rifle, SALVO, etc. are some of the power point acronyms of the era I can recall from memory...then read "The Great Rifle Controversy" by Ed Ezell...

My goal was to make the Marine Corps 100% happy with an improved M16.  1980-1983, been there, done that, got the T-Shirt, tattoo, Challenge Coin, Baseball Cap, and Meritorious Service Medal.
So if only 99% of the Army liked it, I'm ok with that too...I mean the Army bought 100.000's of them...that says something to me...

The removable carrying handle has finer click adjustment changes than does an A2 with a fixed carrying handle. And an M4 front sight post, even though identical to an A2, has larger elevation change than it does on a rifle. So, I recommend the 50 yard/meter zero with either, with the rear sight all the way down (300), or better, "slipped" 2 or 3 clicks past that. Only elevation zero adjustments at this point are to the front sight post. Attain a point of aim = point of impact (POA=POI) zero at 50, then test this at 100 where the POI should be a few inches higher. If you have a 200 range, then verify POA=POI. If the 200 POI is either high or low, fine tune with the front sight. If you started with the elevation "slipped" 2 or 3 clicks below the 300 mark, your have a good 200 zero. Subsequently, to engage a 300 target, then elevate the rear sight to the 300 mark and give it a try. Subsequent range adjustments are made with the rear sight elevation if you have positive/accurate feed back of target impact or miss.  In reality, this zero stuff is not all exact mathematical science because of various types of ammo, bullet weights, etc., in use; and our human inability to be dead nuts on target with eyes only from shot to shot.
Firing position can change zero as well. When I qualified with M14's over the years, my 200 to 300 zeros (what we called "dope" in those days) changed from 200 offhand to the 200 kneeling. And then at 300 my sitting zero was different by a couple clicks to prone rapid fire...all because my cheek weld was different in each firing position.
Another all to common factor at work here is how much training one has had with iron sights (sight alignment, sight picture, etc.) to begin with. I was lucky enough to have been well trained as a Marine Rifleman by expert coaches on live fire ranges out to 500 with hundreds of rounds of live ammo--and in Boot Camp. thousands of rounds "dry-fired"). Not many civilians or LE have been so fortunate.
Hope this helps.
Good Shooting!

Unfortunately, the U-Tube video is but a fraction of what they recorded, so many of the other improvements and changes were not aired. We need to put some pressure on the IMT to re-edit what's left into a Part 2.

That sounds like the Improved AR Zero, so talked-about today.

If this is Neil, emails sent...to your .mil and .com

Roger. Repeat, over...