I certainly do not want to come off as a know it all. You guys have demonstrated that you know a lot more about the Army than I do now or did then.
This is strictly from my memory observation and impressions not research or knowledge of Army Regs.
For reference I was in the Army from 1966 to 1969.
The rank of corporal (two stripes) was as far as I know discontinued prior to my time. I don’t think I ever met a “hard” (actual corporal) A new enlistee was a private E-1, if he kept himself out of trouble many or perhaps even most were promoted to private E-2 upon graduation from basic training. Again if he was with the program and didn’t get into trouble men were frequently promoted to private first class (one stripe) out of AIT (advanced individual training). As far as I remember corporals only existed in training companies and were actually “acting corporals”. After I finished AIT and was a holdover awaiting orders I was a PFC and assigned to a basic training company. The company commander made me an “acting corporal”. I was still a PFC E-3 but wore the corporal stripes as long as I was with that company assigned to assist a platoon’s drill Sgt. I think that this was quite common, because at that time the Army had a serious shortage of NCOs because of the wartime buildup. A corporal E-4 was the lowest NCO rank. As an acting corporal I was considered to be a NCO but only within that training company, and it did not involve an increase in pay grade.
When I left that company and went to an Infantry company in Korea, I reverted to PFC.
After I was in Korea awhile I was promoted to Spec. 4. A specialist 4 was a pay increase from PFC but was not an NCO. My rank was specialist 4 but I had no “specialty” I was just an infantryman.
While serving there the company commander made me an “acting Sgt” (3 stripes) and put me in charge of a platoon (a job normally held by a Staff Sgt. E-6, or a Platoon Sgt E-7) again this was common because of the shortage of NCOs. Again I wore the 3 stripes and was considered an NCO but only within that company. When I left that assignment to go to Vietnam I reverted to Spec 4.
I think that promotion to private E-2, PFC, and Spec 4 were solely at the discretion of a company commander, usually a captain but often a 1st Lt. Promotion to Sgt and above involved a promotion board tests and evaluations and I think had to come from a higher level than the company. I thought that these were means for the company commander to “reward” troops who were doing a good job with a little more money but who were not eligible or ready for NCO.
The “acting ranks” were strictly at the pleasure of the company commander – he did not have to court martial or go through any other channels to “demote” an acting Sgt back to his actual pay grade.
Vietnam was different in that Spec 4s were frequently promoted to Sgt E-5, and Sgt E-5 were frequently promoted to Staff Sgt E-6 (3 stripes and one rocker) without a review or promotion board. I don’t know if the company commander could actually do it on his own or if someone higher had to sign off on it, but these promotions were certainly based on the company commander’s recommendation and were actual “hard” or permanent promotions to NCO ranks.
In my case the company commander called me into his tent, and said “congratulations you are being promoted to Sgt E-5 and will be assigned to lead a team” and that was all there was to it.
When I was ready to leave the company commander offered to promote me to Staff Sgt E-6 if I would extend my tour for another 6 months. (I declined)
Back to the specialist ranks it seems to me that promotions to Spec 5 and above also involved a promotion and review board, and required an actual specialty. Spec 5 and above were not NCOs but were pretty much equivalent to them. My understanding was that specialists were supposed to be in charge of functions or equipment, whereas NCOs were in charge of men. That was the way it was supposed to be but it was definitly not a clear distinction Spec 5’s and above were often in charge of men assigned to them, and were generally treated as if they were NCOs.
To Steve’s original question in a line infantry unit an RTO was often a private, PFC, or Spec 4, with no special radio or RTO training. In Vietnam there was a lot of OJT (on the job training) going on.
LRRPs during my time were different in that ranks were largely ignored. It was not uncommon for team leaders to be outranked by team members. At times Spec 4 were assigned as team leaders and had E-5 and E-6 NCOs who were new to combat and new to LRRPs assigned as team members.