Key Points and Summary: The M16’s early use in Vietnam was a disaster. Troops faced frequent jams, lack of cleaning supplies, and faulty ammunition—failures that cost lives.
-Initial users, like Special Forces and Airborne units, praised the rifle, but when conventional troops received it without proper training or maintenance, problems mounted.
-The Army ignored key design recommendations, including chrome-plated barrels, and switched to dirtier-burning ball propellant.
-By 1967, urgent fixes led to the M16A1, solving many issues. The M16 went from a liability to a legendary rifle, but its troubled start remains a cautionary tale of poor military planning and oversight.
The M16 Was A Failure Early In the War In Vietnam, Why?
The M16 got an awful rap early in the war in Vietnam, and for a very good reason. The weapon would jam frequently at the most inopportune times (is there ever a good time for a weapon to jam in combat?), and many soldiers died because of it.
We’ll never know the exact number, but it wasn’t small. The year was 1966, and this was the first widespread use of the M16.
First Units Using The M16 Loved It
But the story of the M16 begins in 1962. The Air Force purchased 8,500 AR-15s from Colt for their security personnel.
However, due to the US escalation in South Vietnam, small numbers of AR-15s were diverted to the US Army Green Berets and the ARVN (Army of the Republic of Vietnam) units they were training.
The Special Forces and their Vietnamese allies gave the AR-15 high marks with no issues at all. Later, Special Forces units in Military Assistance Command, Vietnam – Studies and Observations Group (MACV-SOG) carried CAR-15s, the shorter version of the AR-15/M-16.
At the Battle of the Ia Drang Valley in late 1965, Colonel Hal Moore, the Commander of the 1/7 Cavalry, said that without the M16, the battle may have turned out quite differently.
As many know, Mel Gibson portrayed Moore in the film We Were Soldiers Once and Young.
As Conventional Units Poured In, The Problems Started
As the US began pouring conventional troops into Vietnam, beginning in 1965 and 1966, the Army changed its M14 rifles for M16s. Units such as the 1st Cavalry Division, 173rd Airborne Brigade, and 101st Airborne Division took the M16 on its first large-scale deployment with US forces.
At first, all was well. But in 1966, reports came out of Vietnam that the M16 was failing its troops.
The main issues were failing to feed, fire, and extract. In October 1966, the Commanding Officer of the 1st Battalion, 2nd Infantry, 1st Infantry Division reported that his troops had many problems with the new XM16E1 rifles “to the extent that confidence has been degraded.”
These reports reached the US. I remember watching a report on this on the evening news when I was a young whippersnapper. General William Westmoreland, commander of all US troops in Vietnam, was requesting more M16s but hearing from soldiers that they weren’t working.
He requested a technical assistance team visit the troops in the field to see the issues and hopefully solve them.
“Appalling Condition”
A decorated Army veteran and part of Colt’s team sent to Vietnam was shocked by what he found. He said he had never seen equipment in such a poor state of maintenance.
Many of the younger troops had never maintained their weapons (a cardinal sin among the infantry grunts) and were never trained on the M16 and how to properly maintain the weapon. Training manuals and cleaning kits were scarce for the troops. Unfortunately, many believed the BS rumor that Colt reportedly said that the weapon didn’t need cleaning.
The Army didn’t help matters by stating in the manual that “an occasional cleaning will keep the weapon functioning indefinitely.” That was criminally incompetent wording. Soldiers and Marines were sending requests to their families for cleaning supplies, like lubricants, patches, .22 rifle cleaning rods, brushes, and picks.
Army Liable For Other Problems Too
The M16’s original designer, Eugene Stoner, Armalite, and Colt, all recommended that the barrels and bores be chrome-plated. But Big Army refused, stating that it was unnecessary and cost-prohibitive.
The Army Materiel Command posted that the stick propellant used in the M-16 ammunition was not viable, even though the SF, ARVN, and Civilian Regular Defense Group (CIDG) were using those without issues—the same with Hal Moore’s troops in the Ia Drang Valley. But the problems began when the Army switched to the same ball propellant they’d used for 50 years.
U.S. Army Reserve Sgt. 1st Class Harrison Brewer, G4 Chief Movements Supervisor for the 335th Signal Command (Theater), fires an M16 rifle on a range at Fort Gordon, Georgia, March 8, 2019. Soldiers from the 335th Signal Command (Theater) headquarters completed warrior tasks and battle drills to include weapons qualification, grenade practice and roll over training during a four-day training designed to increase their warfighting abilities. (U.S. Army Reserve photo by Staff Sgt. Leron Richards)
They asked Stoner his opinion on this development, and he advised against it, but the Army had already decided.
Colt warned the Army that the M16 wouldn’t function as well with ballpowder. But that fell on deaf ears. The ball powder burned dirtier than the stick powder, requiring more cleaning than necessary, which wasn’t forthcoming.
The Issues With the M16 Compounded With Bad Powder
Besides the propellant issues, the poor maintenance of the weapons, and the rusting of the bores, bolt carrier groups, and barrels due to a lack of chrome plating, an issue the Army knew back in the jungles of WWII. The ammunition would corrode in the hot climate of Vietnam.
Finally, The Issues Are Solved
In 1967, the Army was forced to act, and finally, it did. The Army had the parts that needed to be chrome-plated taken care of. The ammunition was worked around by modifying the rifle to work better with it. There were 10 modifications done, including a forward assist to ensure the bolt was firmly seated.
M16 Rifle (M16A2 Version).
Image: Creative Commons.
The result was the M-16A1. And the rifle was an unqualified success. The basic M16 family went through the M16A1, M16A2, and M4 variants to give the rifle a service life that continues to this day.
The Army will gradually replace the rifle with the new XM-7, which is slowly being tested with select units.
The rifle should have been given to the troops with what the Army knew were the right components. And it cost too many lives unnecessarily.
M16. Image Credit: Creative Commons.
About the Author:
Steve Balestrieri is a 19FortyFive National Security Columnist. He served as a US Army Special Forces NCO and Warrant Officer. In addition to writing for 19FortyFive, he covers the NFL for PatsFans.com and is a member of the Pro Football Writers of America (PFWA). His work was regularly featured in many military publications.
