The basic designs of suppressors fall into two camps, and each is either sealed or user-serviceable. User-serviceable is the technical term for “take it apart and clean it.” The two camps are baffle stack and monocore.

What are the ins and outs of suppressors?

  • Suppressors come in many shapes and sizes, but there are two basic designs.
  • These include baffle stack and monocore.
  • There are five levels of sealed suppressors.
  • Cap-welded, Tack-welded, Fully Welded Stack, Fully Welded with no tube, monocore.
  • Generally speaking, the more welding involved in manufacture, the more it costs.

Simply put, a suppressor is a tube with a series of partitions inside that trap the expanding gases and slow their release into the air. This reduces the pressure wave, and thus the noise, the firearm creates.

The full technical explanation involves physics, metallurgy, heat transfer, the chaotic movement of gases under pressure, and we’ll skip that.

Some suppressors are quieter than others. This is due to design, materials, barrel length and powder used in the ammo.
Some suppressors are quieter than others. This is due to design, materials, barrel length and powder used in the ammo.

Suppressor Design And Construction

Making a suppressor is both easy and difficult. It is easy, in that pretty much anything you put over the end of the muzzle will dampen noise. (Which can, in some instances and designs, be against the law without proper paperwork.) It is difficult in that what you use to dampen noise can degrade accuracy, cause difficulties aiming, and can be inconvenient, messy and just plain ugly.

Here’s a look inside a silencer. The design and construction of a suppressor involves baffles welded inside of a tube.
Here’s a look inside a silencer. The design and construction of a suppressor involves baffles welded inside of a tube.

Suppressor designers and manufacturers work hard to make suppressors easy, convenient, good-looking, not harmful to (actually increasing) accuracy, and all this while significantly reducing noise.

The basic designs of suppressors fall into two camps, and each is either sealed or user-serviceable. User-serviceable is the technical term for “take it apart and clean it.” The two camps are baffle stack and monocore.

Baffle Stack

The baffle stack design entails a tube, and inside the tube the manufacturer places a stack of relatively cone-shaped baffles. Back in the early days, there were two versions, the “K” baffle and the “M” baffle. Today, we have more than two, they all work, and the details matter only to those who obsess over fractions of a dB in on-the-range testing. The baffles are machined to have space between them. The spaces they create are the volume into which the gases will expand. The first of these is called the “expansion chamber.”

The baffles can have various shapes, as seen in cross-section, and they can also have holes drilled through them to create turbulence in the gas flow. Turbulence increases efficiency and makes a suppressor quieter, although some argue just how much it matters.

This bin of machined baffles is ready for the next step in the manufacturing process.
This bin of machined baffles is ready for the next step in the manufacturing process.

The baffles must be kept in place, so they are machined for a snug or tight fit in the tube. The tube is sealed with front and rear caps, trapping the baffle stack inside. The rear cap also contains the mount design, either direct-thread or QD.

On a rimfire or pistol-caliber suppressor, the front and rear caps are threaded so you can take the suppressor apart and clean it. If you do not, it will collect powder residue, lube and bullet material, which hardens into an impressive layer. This can build up until the suppressor is only a heavy tube with minimal clearance for the bullet, and no effective baffles left, the baffles now buried under the gunk.

Rifle-caliber suppressors are self-cleaning, and as a result they are not often user-serviceable. They do not need to be, unless the centerfire rifle you shoot uses cast lead bullets. Then, you’d better have a cleanable suppressor on it.

Once cast or machined and then surface-treated, a baffle stack can be assembled into its tube, ready to be a suppressor.
Once cast or machined and then surface-treated, a baffle stack can be assembled into its tube, ready to be a suppressor.

Sealed Suppressor Welding

A sealed unit will have, at the very least, the front and end caps welded to the tube. Generally speaking, more welding creates a more durable a suppressor. There are five levels.

Cap-welded

Here, the front and rear caps are welded on and the baffles are simply pressed into the tube and trapped in place. While the baffles are tightly packed, they are not attached to the tube.

Tack-welded

On these (usually older designs), the baffles are stacked outside of the tube, and the edges welded at two or three points on their perimeters, creating a rigid assembly. The welds are then filed/ground flush, and the baffle stack is pressed into the tube, where the caps then are welded on.

Alternately, the tube can be drilled at spots along its length where the flanges of the baffles would rest, the baffles inserted, and each hole weld-filled with the baffles in place. As a result, each baffle has two or three welded attachments to the tube, through where the holes had been.

Baffles can be simple or complex. If your suppressor can be taken apart, don’t be surprised at what you see when you slide out the baffle stack.
Baffles can be simple or complex. If your suppressor can be taken apart, don’t be surprised at what you see when you slide out the baffle stack.

Fully Welded Stack

Here, the rim of each baffle is welded its full circumference to the next baffle in the stack. The assembly is then ground or lathe-turned to be round again, and then pressed into the tube, where it can be welded in place or the caps welded on, or both. Also, each can be welded in turn into the tube, but this is a lot more difficult.

Fully Welded, No Tube

This is the process used by Sig. They fabricate the baffles such that they have external, cylindrical skirts. The baffles are then fully welded into a stack, and the skirts form the tube that the baffle stack would otherwise be shoved into. This is a process that requires a great deal of precise equipment, but the end result is a suppressor with greater internal volume and less weight, since it does not use both a baffle stack and an external tube.

Monocore

Here, instead of the baffle stack being composed of a series of cone-shaped parts, it starts as a solid cylinder of the baffle material. Then, through the magic of multi-axis CNC machining, the cylinder has gaps, holes, and baffles machined out of the bar stock of metal. This is then inserted into a tube. The big advantage here is that the monocore can be created in shapes that no baffle stack of cones could ever duplicate.

The monocore tends to be a bit heavier than an equal diameter and length baffle stack, but that can be offset by the choice of tube materials and thickness.

One place synthetics can work is as the monocore of a rimfire suppressor. And if the monocore finally wears out? A replacement is not a controlled part, and will cost $20-30.
One place synthetics can work is as the monocore of a rimfire suppressor. And if the monocore finally wears out? A replacement is not a controlled part, and will cost $20-30.

The big advantages are that the extra contours of the monocore can make for a quieter suppressor, and it is easier to make a rifle-caliber suppressor that can be disassembled and cleaned. As a result you can use a monocore suppressor as a multi-caliber compromise, since it is a lot easier to take apart and clean.

There is one other design detail of the monocore that can matter, or not. It is relatively easy to not only make a monocore suppressor that can be taken apart, but also incorporate into the design an external tube that does not have threads on it. The plain tube is the part that has the manufactures name, model number and serial number on it. If, in disassembly or cleaning, you were to damage the threads (easy to do if you have neglected it, and it is carbon-welded into a single part), the threaded parts, the front cap, rear cap or monocore can easily be replaced. The tube, lacking threads, is extremely unlikely to be damaged by such heavy-handed treatment, and thus you do not have the headache of having it repaired.

These monocore designs allow the maker to place the tube threads in different, and often useful, locations. They can even make the tube a threadless sleeve.
These monocore designs allow the maker to place the tube threads in different, and often useful, locations. They can even make the tube a threadless sleeve.
This modern design uses a monocore, and the tube is a sleeve without any threads on it.
This modern design uses a monocore, and the tube is a sleeve without any threads on it.

What’s The Most Effective Suppressor Baffle Design?

Which method a manufacturer uses depends in part on when they began making suppressors, how much they are willing to invest in capital equipment, and what the caliber and use demands. A maker that has been in business for a number of years, with familiar equipment capable of making solid, dependable old-style suppressors, may be reluctant (and understandably so) to invest in a lot of new equipment that will make suppressors only a little bit better than what they make already.

As the buyer, you can decide what type you want, with the understanding that the more welding there is, the more it will cost. If you do not need a fully-welded suppressor, then don’t buy one. A hunter, for example, really doesn’t have a pressing need for a full-auto-rated suppressor. Buying one will entail higher cost and greater weight.

You will be advised by those who claim to be experts that money spent on any suppressor that isn’t full-auto-rated, or adopted by SoCom or SEALs or some other black-bag group, is money wasted. You must, simply must, buy the most rugged, extreme-use, manliest suppressor, or you are a poseur, dilettante, or not serious. Ignore them.

This is your decision, your purchase, and you will be the one using it in the future. Buy what fits your needs, your wallet, and your self-image. If that requires weight, exotic materials and a military provenance, go for it. If not, go for it anyway, and have fun.

Editor’s Note: This article is an excerpt from The Suppressor Handbook by Patrick Sweeney.


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Cut Through the Noise About Suppressors
One of the hottest firearms accessories available today, suppressors are rife with mystery, urban myth and plain old misinformation. The Suppressor Handbook helps you cut through the noise and enjoy the sweet silence of shooting suppressed. Get Your Copy Now