The group that got the ball rolling on reliability were known as the Whiz Kids in the Kennedy administration. A bunch of accountants with no combat experience looked for ways to make the M-16 cheaper. For the jungle the chamber needed to be chromed as it was eventually done. Otherwise rust...
Should have never stopped using napalm or flame throwers. Totally demoralizes the enemy and leads to fewer causalities on both sides. Bad guys run away and good guys don't have to dig the enemy out of defensive positions.
Vet, several years in Vietnam.