Soldiers in Vietnam had a better chance with the M-14. The M-16 was terrible for jungle conditions. .223 "varmit" rounds lacked necessary penetration power when fired into foliage and the gunpowder residue often jammed up the insides.

Some say the change was made to prolong the Vietnam War until all of the money could be made from it.

The early M-16s had serious flaws that were later corrected, and they came with VERY bad advice on required maintenance.