Suppressors – Current State of Technology Part 4

In Part 3 of Suppressors – Current State of Technology, I talked about the importance of the mount. Single point mounts v. two point mounts and quick attach / detach.  The take-away is the overshadowing requirement that whatever mounting arrangement you choose it secure the suppressor to the weapon and maintain suppressor to weapon concentricity under all operating conditions.

In Part 4, I’ll take you through the unique characteristics of pistol caliber suppressors and dispel some ridiculous notions.

Nothing conjures up images of sinister spies and hitmen running about the country side whacking people than a suppressed pistol, and Hollywood has, once again, convinced us that these devices are the tools of clandestine operators and assassins. Take for example agent Jack Bauer, in 24, played by Kiefer Sutherland, operative extraordinaire at the Counter Terrorist Unit based in L.A., of all places. Agent Jack’s favorite interrogation technique is to use a suppressed SIG to shoot the suspect in the kneecap. Well, I suppose if he weren’t doing that he’d be running around Atlanta’s Caribou Coffee Houses with, dad, Donald Sutherland.

Even more interesting than agent Jack is the concept of a suppressed revolver. How many times have you seen films where good and bad guys used suppressed revolvers? Suppressing a revolver has the same tactical advantage as installing a pay-toilet in a diarrhea ward.

Although manufacturers have gone to the extreme in making available tons of information dealing with suppressor technology, I still get 3 or 4 question a quarter from people asking what suppressor they should use with their S&W .38 special. That’s the power of misinformation.

The reality is that suppressors are not evil nor sinister, and many countries in the EU require sport shooters and hunters to use suppressed weapons.

Alright, so why can’t revolvers be suppressed? The reason a revolver cannot be effectively suppressed is that there’s a huge gap between the cylinder and the barrel, which allows hot gases to escape. The Russian made Nagant, M1895, is the only revolver that can be effectively suppressed. It uses a Belgian design that forms a gas seal between the cylinder and the barrel. When the hammer is cocked the cylinder moves forward creating a seal with the barrel, hence it can be suppressed. This made it popular with KGB operators and it was used throughout the Cold War era. Unless you own a Nagant M1895, please get over your desire to suppress your revolver.

I’d like to deal for just a moment with the sneaky clandestine reputation, and a picture is worth 1000 words.

Suppressed Glock 17

 Allow me to call your attention to the bench’s leg, which is 1 inch stock. Using that as a reference we see that the suppressor has effectively added, approximately, 10 inches to the pistol’s 7.6 inch overall length; unless you’re planning to stick it down your left pant leg, and change your name to Disco-Duck, it’s not a real stealthy weapon. In fact, the system is so long that if you were using an isometric hold you probably wouldn’t be able to turn around in a narrow corridor.

Alright, let’s talk about the unique characteristics of pistol mounted suppressors.

The vast majority of pistols sold today are blow-back operated fixed barrel or Browning style actions where the barrel is unlocked and allowed to tip up. For example, SIG, Glock and 1911 pistols all use the Browning action. The barrel unlocks and the muzzle is allowed to tip up. The Walther PPK, some HK models (e.g. P7) and the Beretta 92/M9 (not exactly true but for our purposes let’s go along with it)  use a fixed barrel. The barrel does not unlock and it stays in place with no tilting at the muzzle or breech.

This excellent animation of a 1911’s operation clearly shows the Browning style action. Note how the barrel unlocks and the breech drops to accept a new round.

Your pistol’s operating system drives your suppressor requirements.

Broadly speaking, a pistol’s suppressor can be made lighter using less robust materials because the pressures it deals with are much lower than a rifle. Manufacturer’s also build pistol caliber suppressors that can be interchangeably used on a submachine gun (SMG) and that will take the abuse of fully automatic fire. These designs will generally be heavier with fully welded cores making them more robust. Before you use a pistol caliber suppressor on an SMG or for fully automatic fire it is critically important that you speak with the manufacturer to ensure the design you plan to use will support fully automatic fire.

The vast majority of pistol suppressors thread directly on to the pistol’s muzzle and most pistols, that you plan to suppress, require that you order the weapon with a threaded and extended barrel. The thread patterns are caliber dependent and generally specific to that caliber, but assume nothing and make sure that your barrel is threaded to the suppressor manufacturer’s specifications. The barrel also needs to be extended so there is no contact between the suppressor and the pistol’s frame. Any contact between the two is dangerous and will impede the system’s operation. European thread patterns will generally be metric and left-hand.

Your pistol’s operating system, or action, will drive the type of mount used. Fixed barrel designs only need a mounting piston threaded to match the muzzle thread pattern. I favor the European metric , for example 13.5mm LH, patterns because they are very effective at resisting loosening of the suppressor while firing. The right hand twist, used in the barrel’s rifling, applies a left-handed torquing vector that keeps the suppressor tight on the muzzle.

Pistols that employ a Browning style action require a mount known as a Nielsen Device, recoil booster; there are a number of industry names for it, for example LID. None actually boost recoil.

SWR's LID

The LID’s function is to decouple the suppressor’s mass from the muzzle so that the tipping action of the barrel is not inhibited.

Let’s talk about the individual components illustrated in the picture above. The two cylindrical parts are called pistons. They are threaded on the long side to match the muzzle thread pattern. The piston fits into and is keyed to the housing – this is the large knurled component at the top. The piston slides into the housing short end first. The spring then slides over the piston and into the housing. Finally the threaded bushing slides over the piston and threads to the housing holding the entire assembly captive. When the pistol fires, gas pressure pushes against the blast baffle. This is the name for the first baffle it encounters in the suppressor tube. The initial impulse, compresses the spring in the LID and when the spring returns under its own pressure it lifts or decouple the suppressor’s mass from the muzzle so that it does not interfere with the action. With out a LID or recoil booster, the pistol would have to be cycled manually.

This video clip will help you visualize its operation.

You are now armed with sufficient information to understand the peculiarities of pistol caliber suppressors. As always, if you have any questions, post them or e-mail me directly and I’ll answer them for you.

In my next post, I’ll introduce you to several companies that I consider industry leaders. These are companies with a significant number of patents and posses the depth and breath to be serious players in the industry.

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