Read #### Culvers account of the M-16 in Vietnam and after. He used it as a Marine Rifleman and i would say if there were more like him, the US Marine Corp would still be issued M-14s,or equivalent. Great writing on alot of the teething problems like having slam fires on dirty chambers,changing powders mid stream being the cause, and having two rifleman having this happen in 5 minutes in his platoon during a firefight. Alot of problems being corrected while a shooting war was going on and the subsequent new problems following.
The engineers and other support troops being the most popular people because they still were issued the m-14 and the Rifleman wanted them. The M193s accuracy improvement going from 1/14 to 1/12 but the tumble wounding effectiveness loss accordingly.
Qualifying on the range being in the butts at the Marines 500 yd max riflemans distance and having the M193 unable to penetate the target backing fillers used. He said the Marine Rifle squads effectiveness was reduced from 500 yds to less than 300yds with the M-16. He states that the M-16 s accuracy was never a problem after 1 in 12 and faster. ETc, ETc
If you want to see where the AR came from and where it is today , it's a good read.