My old, dear friend, Mike W’s comments the other day about the venerable old silenced Colt Woodsman, took me back. They were used in World War 2 and again in the SE Asia conflicts (Viet Nam, Cambodia and Laos). As Mike W points out, a shot through a target’s ear (silenced) provided the desired results for the somewhat underpowered – yet effective – .22LR.

Then there was the High Standard Company,  founded by Carl Swebilius in 1932. Swebilius, an experienced engineer and foreman, had also worked for both Marlin and Winchester. At the outbreak of the Second World War in 1939, High Standard Model B pistols began to be exported to Britain — these hand guns were the first to be modified. In 1942, the U.S. War Department purchased High Standard’s entire inventory, regardless of model, to keep up with demand new simpler and faster to produce models were developed. The Model HD became the most manufactured with 34,000 made by the end of the war.

Initially, the OSS used .22LR Colt Woodsmen paired with old suppressors made in the 1920s by the Maxim Silencer Company, but the Woodsman’s long barrel and the additional length of the suppressor were not ideal for clandestine warfare. As early as 1942, the British had adapted Model B pistols by adding an integral suppressor enclosing the entire barrel, effectively halving the weapon’s length. In 1943, the OSS requested a similar weapon. The result was the Model H-D M(ilitary)/S(ilenced) or HDM/S. The technicians at Electric Bell Laboratories developed by the new gun’s suppressor. Its manufacture was completed in secret and the guns themselves were code-named Impact Testing Machines.

I personally found that the Woodsman was more reliable than the High Standard. The HS had problems with the sears wearing prematurely and it would result in five rounds or more (suppressed) splashing out onto a target. While it did have a colorful effect, that’s not quite what you want to happen. You could fire it single-shot with the lock engaged, avoiding that problem. More on that below.

Back to the High Standard Impact Testing Machines. They were 13.8 inches in length, weighed 48 ounces unloaded, and had a 10-round magazine. Unlike stock High Standard pistols the HDM/S had a slide lock that could be used to prevent the gun from making a sound by locking its action closed, making it a near silent single-shot weapon. The barrel was ported with four rows of eight (later 11) holes. From these holes the propellant gases from the fired cartridge escaped into a zinc-plated bronze mesh, which acted as a heat sink that slowed the gases exit from the muzzle. Closer to the muzzle, a second chamber was filled with bronze wire screens further slowing the exit of the gases.

The OSS filled the second chamber with liquids such as water, oil, or even shaving cream and sealed the muzzle with tape. This maximized the efficiency of the suppressor and the only sound heard when the pistol was fired was the mechanical function of the action. The suppressor could reduce the pistols report to as little as 20 decibels — about as quiet as a person whispering. The mesh and wire screens would last for up to 200 rounds before they needed to be replaced.

During the Vietnam War, the .22LR suppressed High Standard pistols were used by the Studies and Observations Group, CIA, Army and Navy Special Forces. Along with the Colt Woodsman, they were one of a range of suppressed weapons deployed and found use assassinating enemy officers and Communist Chinese observers, during snatch raids to capture high-ranking prisoners and in shallow penetration raids into Laos and Cambodia. Perhaps the highest-value target killed by a High Standard pistol was a North Vietnamese People’s Minister of Mobilization, shot in a crowded Hanoi square — the operative who shot him escaped unheard and undetected.

In 1967, they underwent a retrofit to use a new suppressor developed by Frankford Arsenal, however, these proved less efficient and more bulky than the original Bell Labs design.

The Hush Puppy

1967 was also the year that the US Navy began to send Smith and Wesson Model 39 semi-automatic pistols to Viet Nam for the use of SEAL Teams. The Navy had a supply of 9mm ball ammunition that was used in the Karl Gustav (Swedish K) SMG, and that was used in the Model 39, which when silenced with the Mk 3 suppressor, became the Mk 22 Hush Puppy. As with its predecessors, it had a slide lock to allow it to be fired single-shot (far more silently than if the slide racked and ejected brass).

The cans on the Hush Puppy needed new internals about every twenty rounds because the seals just didn’t last, and higher sights had to be installed to see over the silencer, and they’d hang up on things at times. BUT all in all, the Hush Puppy was an improvement in the power of a silenced pistol over its predecessors which were chambered for .22 LR.

The H&K Mk 23, still in US Navy inventory, is a larger and heavier pistol, chambered for .45 ACP, that was originally issued in 1991 and did not have a slide lock. Other, subsequent entries into the silenced handgun world followed (lighter weight) and the details of those weapons and how they have been employed, including specifics on subsonic ammunition, remains classified. All classification notwithstanding, the basics remain the same.

 

21 COMMENTS

    • An ancestor of the Colt Woodsman, but a contemporary of the High Standard. You could make them at home if you were a machinist, but that would be illegal.

  1. An interesting read. I was very disappointed when can reform fell by the way a couple years ago. I prefer to keep BATF out of my life as much as possible. I do have a soft spot for the M39 and the M39-2. I like the way they feel in my hand and how they shoot.

    • I didn’t get into the .22LR stinger for that very reason. It’s a pen gun that is fired at point blank range into the temple or ear of the target. They’re made cheaply and were intended to be dropped before the days of gunshot residue testing…

  2. This is a really fascinating post, Larry. A suppressor that drops the sound to 20 dBA is amazing. I think that the ones we can buy these days will knock 30 dB off the report. I can’t say I research them a lot, but I’ve never one that said it would knock off 40dB. A .22LR rifle is in the range of 120 dBA, and knocking that down to 90 or maybe 85 is helpful but it’s in a different universe than 20!

    Unlike the majority of your readers, I couldn’t read about the sear on the HS letting out five rounds and creating a “colorful effect” without thinking about Steve Martin as Vinnie in “My Blue Heaven” talking about using .22 in the ear to kill other mobsters. “See, a 45 will blow a barn door out the back of your head and there’s a lot of dry cleaning involved, but a 22 will just rattle around like Pac-Man until you’re dead.”

    • That’s precisely what a .22 LR round will do. They deflect off this or that and bounce around inside of a body, particularly a skull.

  3. Very interesting…especially to my “non-gun” knowledge brain. To SiG above, married to a veterinarian, she was explaining to the State Police (and others who watch too many movies) to NOT shoot an injured horse between the eyes…the skull cap is too thick and the round will bounce off, or worse, add further injury and suffering. Through the eye is best regardless the round.

        • The effect on a brain from a non-lethal and non-penetrating shot into the skull is highly traumatic. Again, I’ve seen the results on human beings. I’m sure that it’s similar with a horse, cow, etc. So when we talk about surviving a gunshot, it doesn’t mean that they won’t have short term problems as a result of the impact(s). Maybe Dr. Dan or Dr. Mike_C want to weigh in on that at some point.

          Premaco – https://www.latimes.com/archives/la-xpm-1988-06-24-fi-5985-story.html – is an interesting case. A USMC Lieutenant, son of the FBI Special Agent-in-Charge of the Reno office, and another former marine took a contract on Bill King, mentioned in the article. He shot King in the eye with a .45 ACP at point blank range, and while it messed him up, and he lost the eye, King lived. The LT and his accomplice also killed King’s wife and a business associate named Oates. I spoke with King after he got out of the hospital and he was moving to Arizona with his children. I don’t know what became of him. https://www.latimes.com/archives/la-xpm-1991-07-02-me-1731-story.html

          • Similar to your mobster account who survived.

            This narrative of the Left that “deadly force is unnecessary” is typical coming from those in the cheap seats operating from feelings, behind their security details. None of them haven’t a clue about engagement (and thankfully I have not been in that situation, but I know I’d do what it took to clear the threat, even if I only had my Stiletto framing hammer – same striking force, half the weight.)

          • The FBI SAC in Reno claimed not to have known anything about the murder contract that his son took from the Vegas Mob.

          • I have always been taught that when dispatching an injured animal or butchering a restrained one to “make an x” between opposite ear and eye and shoot it there. Over the years I have dispatched several hogs and cows using either the .22 or the.38 with complete success!

          • Sorry. I don’t know anything in particular about nonlethal GSW trauma to the brain. (Other than the obvious “don’t be the guy who gets shot”.)
            /hangs head in shame

  4. Howard…[not to get too deep in the weeds on this]…yes, the ‘X’ will work on horses, the front cap is very thick on mature horses for natural protection so you have to use a large caliber, otherwise the eye slanted back towards the brain is safest when a smaller caliber is all you have. (Think this is morbid, dinners with rancher neighbors and my wife as the vet (I’m the help)…no animal subject is off limits, some serious, some really funny.)

  5. Thanks for the history lesson, LL!

    I’ve never fired a suppressed weapon, or a full-auto one, so this is interesting reading.

    Hiram Percy Maxim developed the silencer based on his work with other sorts of “mufflers”. HPM was also an Amateur Radio Operator of the highest caliber (no pun) with the callsign 1AW. He founded the American Radio Relay League, which uses W1AW as it’s callsign, and was instrumental in keeping Amateur Radio on-the-air after WWI.

  6. Most noise-producing machines use mufflers integral to the base machine.
    Examples include motorcycles and chain-saws.

    Why are firearm mufflers available separate from the machine they muffle?
    Why are firearm mufflers taxed and regulated?

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