Frontline Vietnam: The M16A1 5.56mm Rifle

Nathaniel F
by Nathaniel F

Vietnam saw the introduction of the M16 rifle – the US Army’s first rifle of caliber smaller than .30, and its first automatic rifle issued to every man in the rifle squad. What was advertised as a huge step forward, however, has become one of the most infamous moments in Army procurement since. To this day, the AR-15 rifle family bears as a black mark its premature and mismanaged introduction to service. The rifle, issued with ammunition of an entirely new type that was not yet held to proper military specifications for case hardness and pressure, advertised to the troops as “low maintenance”, and not yet equipped with a chrome-lined bore or chamber, produced disastrous results for many soldiers and Marines equipped with it.

The Ichord Committee report would identify many of these issues, and – too slowly – action was taken to help remedy the rifle’s faults. One such action was this training video on how to maintain and keep in operation the M16A1 rifle. The video as hosted on YouTube does not have a date attached, but it was originally produced in 1968 under the title “Rifle, M16A1 Part II – Field Expedients”:

We can see in this video a dramatic shift from the initial official attitude towards the M16 rifle. It is no longer advertised as “low maintenance”, an overview of recommended and field expedient cleaning supplies (including toothbrushes and pipe cleaners), and procedures for cleaning the moving parts group (interestingly, disassembling the bolt group in the field is not recommended), chamber, and magazines are identified. Some of the suggestions, such as washing out your rifle while under fire, still seem almost tragically optimistic, however.

Over all, keeping the chamber clean is emphasized. No wonder, too; of 250 interviews conducted for the Ichord report, 50% of troops reported having serious malfunctions with their M16 rifles, and 90% of those malfunctions were reported to be failures to extract. Simply put: The unchromed chamber of the early rifles were not up to the conditions experienced in Vietnam without routine, thorough maintenance with relatively specialized tools. Those unfortunate ones who were issued rifles early on, before cleaning supplies were widely disseminated, must have loomed large in the minds of the video’s creators.

With the addition of first chromed chambers, then totally chrome-lined bores, and tightening of the ammunition specifications of the M16 rifle, it did overcome these issues and eventually regained much of the respect it lost between 1965-1968. Unlike the AK rifle, M1 Garand, or even M14, the M16 did not have a traditional development cycle, complete with major non-combat troop trials and a cycle of improvements. The M16 had its baptism in combat in Vietnam, where there was no room for the growing pains of youth.
H/T, The 5.56x45mm Timeline.

Nathaniel F
Nathaniel F

Nathaniel is a history enthusiast and firearms hobbyist whose primary interest lies in military small arms technological developments beginning with the smokeless powder era. He can be reached via email at

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  • Ray worsham Ray worsham on Mar 03, 2015

    Hey, Nathaniel it is "loomed large"...and good thing it did. That speaks well of those men.

    • Nathaniel F. Nathaniel F. on Mar 03, 2015

      @ray worsham Thanks for the correction; it was a typo I didn't catch!

  • Screwtape2713 . Screwtape2713 . on Mar 04, 2015

    You know what I have found absolutely fascinating when reading this article and others (such as the discussion with Jim Sullivan and Daniel Watters) regarding the early problems with the M-16, the chamber specs, the ammo specs and so forth?

    If you rolled the timeline back 50 years to WW1, substituted "Canadian army" for "US army" and blotted out the name of the firearm in question, you could just as easily be describing the Ross rifle debacle...