I served two tours in RVN sir and the first was with Special Forces. I knew many folks that gave me first hand accounts of the M-16s initial shortcomings; hardened SF combat vets, not uncredible third party stuff. This lead to a Congressional investigation and several changes to the weapon. When I arrived in country the end of '68 this controversy was fresh in the mind of a lot of combat infantrymen.
I began in Special Ops in SF; we fired and maintained almost every American made weapon from WWII on. Later, on two successive A-teams, our CIDG were armed with those weapons. That is M-16s to carry, but .30 cal water cooled MGs and 50s on the permiters; 60 and 81 mm mortars; BARs, greese guns and you name it. We also fired and sometimes carried the weapons of our foes. As a matter of fact, we trained by having those weapons fired over our heads so we could recognize them from down range and give accurate reports when receiving fire from them.
Of the choices I had in Special Ops, I preferred the CAR-15. It was a very effective close in weapon. I carried seven magazines of 5.56 per canteen cover; five canteen covers on my web gear. I carried another 250 rounds in my ruck sack. With the M-1 or M-14; I could never carry 1,000 rounds along with all the other gear needed to go behind enemy lines for 5 to 7 days. BTW, I used the forward assist plunger on more than one occassion to clear a round.
Best,
Dave
Here is some more background from Wikpedia.
Secretary Robert McNamara ordered a halt to M14 production in January 1963, after receiving reports that M14 production was insufficient to meet the needs of the armed forces. Secretary McNamara had long been a proponent of weapons program consolidation among the armed services. At the time, the AR-15 was the only rifle that could remotely fulfill a requirement of a 'universal' infantry weapon for issue to all services. McNamara ordered the weapon be adopted unmodified, in its current configuration, for immediate issue to all services, despite receiving reports noting several deficiencies with the M16 as a service rifle, including the lack of a
chrome-lined bore and chamber, the 5.56 mm projectile's instability under Arctic conditions, and the fact that large quantities of 5.56 mm ammunition required for immediate service were not available. In addition, the Army insisted on the inclusion of a
forward assist plunger to help push the bolt into battery in the event that a cartridge failed to seat in the chamber through fouling or corrosion. The original Armalite already had a chrome-lined chamber to prevent corrosion.[
citation needed] Colt on the other hand, had argued the rifle was a 'self-cleaning' design, requiring little or no maintenance. Colt, Eugene Stoner, and the U.S. Air Force believed that a forward assist needlessly complicated the rifle, adding about $4.50 to its procurement cost with no real benefit. As a result, the design was split into two variants: the Air Force's M16 without the forward assist, and for the other service branches, the XM16E1 with the
forward assist.
When the XM16E1 reached
Vietnam with U.S. troops in March 1965, reports of jamming and malfunctions in combat immediately began to surface. Although the M14 featured a
chrome-lined barrel and chamber to resist corrosion in combat conditions (a danger learned from WWII
Pacific theatre combat experience), neither the bore nor the chamber of the M16/XM16E1 was chrome-lined. Several documented accounts of troops killed by enemy fire with jammed rifles broken-down for cleaning eventually brought a Congressional investigation.[
citation needed] Later investigations also cast doubt on the veracity of the original 1962 reports of the alleged stopping effectiveness of the 5.56 mm bullet, as well as criticism of inadequate penetration (in comparison to the
Soviet 7.62x39mm round) when firing at enemy personnel through light cover.[
citation needed]
On February 28, 1967, the XM16E1 was standardized as the M16A1. Major revisions to the design followed. The rifle was finally given a chrome-lined chamber (and later, the entire bore) to eliminate corrosion and stuck cartridges, and the rifle's recoil mechanism was re-designed to accommodate Army-issued 5.56 mm ammunition. Rifle cleaning tools and powder solvents/lubricants were issued. Intensive training programs in weapons cleaning were instituted, and a
comic book style manual was circulated among the troops to demonstrate proper maintenance.
[7] The reliability problems of the M16 diminished quickly, although the rifle's reputation continued to suffer.
[7] Moreover, complaints about the inadequate penetration and
stopping power of the 5.56 mm cartridge persisted throughout the Vietnam conflict.[
citation needed]