The M-14 was underrated and never got the opportunity to evolve, like the M16 did. Had the M-14 gone through the design evolution that the M16 experienced, who knows what would have transpired. The M-14, incidentally, did away with the M-1 Garand “ping” due to its detachable box magazine.
Something else that never gets mentioned: The Israeli Defense Forces replaced their domestically manufactured Galil, which has the Kalashnivov action, with the M-16. AK fans claim the decision was purely economic, but I remember reading that the IDF put the two rifles through head to head tests and found the M-16 to be more desirable. They had no problem with its reliability evidently.
Incidentally, my admiration for the M-16 does not extend to the M-4 Carbine, which, from all accounts, has reliability problems stemming from its short barrel, which causes the gas system problems. I think the M-4 is a mistake.
The M-14 in my opinion is the most accurate semi-automatic ever made. Used to have one, too heavy for deer hunting, geez, getting old. Carry an AR-15 now. Funny we shipped 8,000 M-16s to the Israelis for distribution to the Palestinian Defense Force, first thing they asked for and threw away their AKs.