I read some articles about the M16. They said that the first M16s were really bad and that they jammed a lot. I also read that lots of soldiers replaced their M16s with any weapon even with AKs from the NVA and Vietcong. I want to know how often did the M16 jamm, how often did the American soldier replace their M16s for other guns and lastly when did the M16 become good and reliable, how long did it take to remove the issues it had in the first years of the Vietnam war
The M16 did have a lot of problems during the early years of the Vietnam War but this wasn't due to the design of the gun per se so much as it was a problem in US military procurement. During acceptance trials the M16 performed exceptionally well, able to cycle tens of thousands of rounds without malfunction. However, in between those trials and adoption a few tweaks were made. One of the most crucial was in the formulation of the ammunition. The ammo used in the trials used tubular (or stick) nitrocellose powder. The companies contracted to produce ammunition for the US military were unable to provide that variety of powder in the quantities required so instead substituted a spherical or "ball" powder. The use of this powder produced a much higher level of fouling for the gun, exacerbated by its direct impingement design. In combination with the decision to issue the gun initially without cleaning kits and the choice not to chrome plate the chamber of the gun the result was a disaster. M16s in the field would jam (due to fouling) and the malfunctions could not be easily and quickly remedied in the field. This led to the creation of a very poor reputation for the M16 even though the overall design of the gun wasn't necessarily at fault, and with the correct ammo and proper maintenance the gun would have been fine (as later use of the same gun design has proven).
Most of the major problems with the M16 platform (ammunitino, cleaning kits, etc.) were addressed by 1968 though it would continue to have some level of problems through to the present day. The major issue is that the AR-15/M16 system is very sensitive to design changes. There are some variants which are incredibly reliable and robust, and there are others which are only slightly different which are not as reliable as would be desired for a service rifle.
Additionally, it was not at all common for US soldiers to use captured AKs as a replacement service rifle. Such things happen occasionally in all wars, but it was not as common in the Vietnam war as it has been made out to be.
Thank you all for taking time to write these comments! I appretiate it