The Suppressed M16 In Vietnam And After


“With the emergence of  the M16 as the principal infantry arm of the  US ground combat forces in South Vietnam, the  major thrust of suppressor development was centered on the 5.56mm rifle.     The USAMTU had been actively involved with suppressor testing during the course of Army revaluations.     So far as the AMTU was concerned, if there were certain benefits to be gained by field use of a suppressor-equipped M16 rifle, then fitting a similar device to an accurized rifle “offered endless possibilities” for combat use in Vietnam. ”  -Senich

While suppressed guns had been used in past wars ,their use and development during the war in Vietnam was the golden age of silencers in use as  more than assassinations or sabotage special missions.     The effectiveness of  long range fire on enemy at night or day light  with out being able to determine true range or direction  can not be questioned .  The impact of the effectiveness of  knowing friendly troops have suppressor equipped rifles even has an effect to their fellow soldiers.  “ I would see these guys from time to time, they would come in just after first light and I couldn’t help thinking how damn glad I was they were on our side” To many US troops the sight of other US combat personnel with suppressed rifles made and impression.

Even though rack grade M16s with suppressors had been issued for specialized units for covert missions  and regular forces for long range  patrols, recon, and ambush missions  no official organized program existed for fielding optic equipped suppressed M16s.  Examples of M16s with optics and suppressors are seen in many pictures, but usually this was an example of individual initiative or small  units going about it in a quasi official manner.

Official documents from as early as May 1966 show that a program to field suppressed M16s to RVN  had began. The USARV submitted an ENSURE request for “silencers for the M16A1rifle.”  Even so,  it took a considerable amount of time  before examples were sent to RVN for combat testing.

Most of the examples sent to VN for testing and use are the   US Army Human Engineering Lab, Frankford Arsenal  and Scionics inc.   After testing  it was concluded that all models did reduce  a noticeable amount of muzzle noise from the M16, they all also came with issues and an increased in cleaning.

During the testing and fielding it did not take long for users to bring up the idea of sub sonic ammunition to increase the effectivness of noise reduction.   From the book by Gary Douglas , A LRRP’s Narrative.

” I let Crowe carry my M16 with silencer. We had a number of 556mm rounds bootlegged, using low velocity powder and soft lead bullets that did make the suppressor quite effective .. The lead bullets worked fine, except for the one drawback. You had to hand cycle each round. “

Of course making sub sonic ammo is well thing the means of ammo producers  or handloaders but making sub sonic ammo that would cycle the action of  the rifle is another matter Not to mention the obvious requirement for effective terminal performance and range.    One problem encountered  was with making sub sonic ammo was the now empty space inside the case.  They found quickly that if the bore was pointed down, the powder would fall to the front of the case away from the primer resulting in failure of ignition or delayed ignition.

 “A concerted effort was made to develop suitable subsonic ammunition. However, a major problem  came as a result of the reduced powder loading.  When the M16 round was down loaded there was only a small amount of powder in the case, When the weapon was angled downward the powder showed the tendacy to move forward in the case, away from the primer and ignition was either irregular or nonexistent.  I was necessary to emply filler on top of the powder charge, Numerous substance such as oatmeal, cream of wheat, and cotton were tried; all with disastrous results. After firing a few rounds the rifle gas port and suppressor became clogged with the inert filler.” Donald G Thomas  -Scionics

The method to finally cure this was to use an epoxy inserted into the case in a way that left a small central cavity for the powder.   An effective but very time consuming and expensive.  The end result being that the vast majority of suppressors used and issued during the war  were used with standard service ammunition.

By the end of the War , the Scionics MAW-A1 suppressor was the model deemed the most suitable  and durable for  use on the M16 rifle.

The suppressed M16  became a very effective tool for operations in South Vietnam, especially for small recon  teams.  My mentor served  in a ranger company on LRRP missions in the 199th Brigade and carried a suppressed  M16.   He tells of ambushing a group of Viet Cong one night while cooking their dinner.

M16 suppressed

” They were about 5o yards away and it was  almost night . They were sitting around a fire cooking and smoking dope.   One had his back to me and I shot him in the back of the head.   He immediately fell over onto the fire and  the look on the faces of his friends was pure terror. The shock of being sprayed with their buddies head, not hearing the shot  and being stoned really took its toll Then the rest of the team opened up on them “

He was made more or less the team sniper and liked the suppressor and M16 combo.  He did say that in an emergency fight  he had to fire on full auto and at a certain point the suppressor blew off the end of the barrel and “took off like a rocket”.

The Army would take some time before getting serious about suppressing  M16 family of weapons for general or sniping use.   It went on to focus on the Xm21  system and a suppressor for it.  This  combining  762mm semi auto rifles and suppressors  of course went on to be more fully realized in the M110.

The concept of the M16 with suppressor was and is just too good to die.   The military went on to field the KAC NT4 suppressor for the M4 and MK18 carbines.   The with the more perfected idea from Vietnam of the M16 with suppressor in the excellent MK12  special purposes rifle using the  Opcs inc. suppressor.  Perhaps what many user in  the Vietnam wished for.

All of the previous systems are no longer used or being phased out of  and being replaced with  newer designs.    But the AMTU’s idea of a suppressed M16 is still as valid and useful as it was in  the 60s.


  1. It’s “Sionics”, not “Scionics”. Mitchell WerBell was the founder, and it stands for “Studies In the Operational Negation of Insurgents and Counter-Subversion”.

    WerBell was a character–Former OSS and CIA, with a decidedly spotty reputation and record. Some of his work was borderline fraud, some was excellent. They were the guys who did the initial bunch of suppression work on the Ingram SMG systems, and were also tied in with COBRAY, another WerBell effort.

    Dude was reportedly assassinated with Digoxin by Larry Flynt and another nutbar. Like so much of the fringe around these things, you read the histories of the involved parties, and you’re left going “WTF, man… Just… WTF?”.

    The reports and stories are all over the map. WerBell was supposed to have claimed to be a high-ranking officer in the Royal Afghan Army, at one point in his life. Seriously shady stuff, when you get down to it.

    Of course, when you look at it all, there’s shade everywhere. Take, for example, the initial fielding reports from Vietnam on the M16’s earliest iterations…

    And, let’s leave aside the entire highly dubious proposition that silencing your infantry weapons is a generally good idea. Somewhere, there’s an account out there about a guy who took a silenced Swedish “K” submachinegun (or, and S&W M76…) out on a LRRP mission, and had the signal experience of the VC/NVA who were pursuing said patrol not noticing that they were dying when taken under fire, which did jack and shit to discourage the un-hit parties from continuing the pursuit. The accompanying Little Brown Killing Machines were also not encouraged by the lack of signature effect, which had negative effects as well.

    The noise factor has rather more effect than many of us think. I remain dubious of the entire proposition of silencing everything, all the time. I think you need to be able to make noise, and also be capable of operating suppressed, as needed. You also have to add in the “Should I, or shouldn’t I…” thought process in to your tactical planning for when to run suppressed and when to run full-bore.

    TBH, I also think there’s room for a “loudener” and a “flash enhancer” under certain circumstances. Rather more of combat is purely psychological than many think; you want to be able to meter things out such that you’re taking maximum advantage of that fact.

    • The story about the suppressed Swedish K comes from John Plaster in his book “SOG: The Secret Wars of America’s Commandos in Vietnam.” It’s his own account from running recon in Laos. He went to a CAR-15 after that.

      • I couldn’t remember the citation for that one… Thanks.

        Although, I could swear I heard it first-person, too, and I never met John Plaster… Might-maybe have been someone who either experienced the same thing, or who’d taken up the Plaster anecdote as their own.

        My mind is a garbage-heap of information that I can’t remember the precise provenance for. There’s stuff I read years ago or heard, but I’ll be damned if I can remember the when, the where, or who I heard it from.

        • If your mind is a garbage heap, I’ve gotten a lot of value from picking it over. I’m reading my way through Hognose’s archive chronologically and I recently got to the point where you started commenting there. Your comments provide a significantly higher signal:noise ratio than typical.

          Thanks for the tip on WerBell. I read his Wikipedia bio. Interesting dude, for sure. He’d make for a pretty interesting bio. That era of drugs, assassins and mercs in the CIA and fellow-traveler orgs is stranger than fiction, not least because separating out the truth from the fiction is pretty difficult.

          • Appreciate the feedback, and I’m glad you feel I have provided some small value in return for wading through my verbiage… 🙂

            Friend of mine once remarked that it was probably a major regret for my parents and teachers that they’d taught me to talk, read, and write–Because you simply can’t get me to shut up or write succinctly on something, once you get me started.

            Ah, well… I think someone in the family tree probably actually ate part of the Blarney Stone, as opposed to having merely kissed it.


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