How do suppressors work?

[inbox485]

I've skimmed through responses and didn't see the short and simple answer.

A silencer uses a series of baffles to convert sound energy into thermal energy.

 

[Riss]

Wahoo got it all right. You all need to go back and read either his post or all 3 books written by Al Paulson on the subject. It is not the baffles converting the sound into thermal energy. It is (partially) the surface area of all of the baffles soaking up the heat and cooling the gasses which helps to reduce the amount of gasses that are released. This and the delay in how fast they are released, and change in the frequency of the sound that they make to a range which is less easily heard by the human ear. Many, many things are factors in how a suppressor works, and many of the things listed prior are simply not involved.

 

[Ranb]

Of Paulson's books on silencers, I have only seen these;

Silencer: History and Performance, Volume 1: Sporting and Tactical Silencers
Silencer History and Performance: Cqb, Assault Rifle, and Sniper Technology
Firearm Suppressor Patents: Volume1: United States Patents (Paperback)

I have not seen a volume 3 for silencer history and performance. Where did you get yours? Thanks.

Ranb

 

[Ranb]

I've skimmed through responses and didn't see the short and simple answer.

Read more, skim less My first post on how they work had this near the top; "It is that simple, cool and expand, just like a car muffler."

There is some bad info in this thread, but lots more that is good and useful even if it does not directly pertain to how silencers work.

I recommend that any shooter interested in enhancing their experience try out a good quality silencer sometime if it is legal in their state. Do not let anyone discourage you by saying they are illegal or too difficult to own. It is a routine and easy matter.

Ranb

 

[Riss]

There are 3 books and I think that you just named them all.

 

[Ranb]

Opps, I heard there was a Vol 3 of Silencer History and thought you were referring to that one. Do you have the silencer patents volume? Does it have drawings of modern designs?

When I got the first book, I was dissappointed to find that it was not a "how to" book or a reference on modern designs, but am glad I got them both just the same.

I am always on the lookout for something new to make on my lathe, and it seems that the most usual good sources are those people who make them as a hobby like myself. One of these days I have to get a good meter and post results.

Ranb

 

[Gideon]

Some of the ignorance displayed in this thead is scary. A quick search will give you the answer. To think anyone would think the bullet would ever touch any part of the suppressor

Car muffler, disruption of sound waves, etc. A suppressor simply baffles the sound waves being produced from.

1. Sound from the mechanical operation of the gun
2. The pop of the primer and burning of the powerder charge
3. and to an extent the sound from breaking the sound barrier

No suppressor suppresses all of the sound, so the quieter the mechanics on a gun and the less of a charge going off (.22 versus .223) and whether you have a sonic boom or not all factor in.

If a bullet hits one of the baffles inside it's called a baffle strike and it's a bad thing that can damage or even ruin a suppressor. there are all kinds of different baffle designs but basically you're trying to capture the sound waves and turn them back on themselves in a confined space until you have some level of dissapation.

Gideon

 

[Riss]

The best how to books are actually not how to books anyhow. If you want to build one then looking through all of the patents and construction diagrams is required, also the theory, physics, and basic how they work books are needed.

 

[Vern Humphrey]

1. Sound from the mechanical operation of the gun

Suppressors do not suppress sound from the mechanical operation of the gun. In fact, many guns suppressed for special operations have locks that prevent the gun from cycling and ejecting the fired case for just that reason.

2. The pop of the primer and burning of the powerder charge

Neither of these are significant -- what is significant is the excape of high pressure gas at the muzzle, and it is this high pressure gas that the suppressor modifies.

3. and to an extent the sound from breaking the sound barrier

Suppressors cannot affect the sonic crack because that occurs all along the bullet's trajectory -- as long as it remains supersonic.

Suppressors suppress only the sound of escaping gas at the muzzle.

 

[Owen]

what Vern said

 

[DaveBeal]

Some of the ignorance displayed in this thead is scary. A quick search will give you the answer. To think anyone would think the bullet would ever touch any part of the suppressor

From the Wikipedia article on 'suppressor':

Wipes are inner dividers intended to touch the bullet as it passes through the suppressor...​

 

[cornman]

Is there a way to manufacture a gun that makes it quiter but not necesarilly a silencer? I would think there would be a market for that. I hate shooting anything but a .22 rifle because of the loud noise.

 

[Ranb]

Longer barrel and a lighter powder charge makes for less noise. Think 22CB and a barrel greater than 16 inches.

Ranb

 

[Al Thompson]

Cornman, I would think that something like a 40 inch barrel would help. Or you could spring for ear plugs.

 

[Confederate]

Everything I know about suppressors I learned from GET SMART. You just screw it on to a revolver and it goes pffft...pffft...pffft so you can hear what 99 is saying to you on the shoe phone.

What could be simpler?

For a suppressor to work, it doesn't necessarily need to reduce the speed of sound. A crrrrkkkk usually doesn't attract the attention a full-fledged Bang! does. Someone might look up and wonder what it is, but they'll usually go back to what they're doing and not give it much more of a thought. If they hear a Bang! without the crack, they also tend to dismiss it...maybe as a backfire.

So suppressing the bang or the crack will yield benefits. If you search on YouTube, you can see how quiet some suppressors are.

Police in some cities fear knives more than guns because they're silent. Gun shots can be detected far more easily by experiened soldiers or LEOs. To get a good bearing you need to hear at least two shots.

Suppressors can be effective in many situations and a good machinest can figure out how to make them. I would think expanding gas would be harder on the eardrums than the sonic boom, but I don't know. I do know that reducing velocity also reduces effectiveness.

 

[Ranb]

a good machinest can figure out how to make them.

You don't even have to be that. I bought a metal lathe several years ago just to make silencers. The only experience I had working metal on a lathe was on the one I bought, and I only fiddled around for a few hours cutting tubing and barstock to get a feel of it. I learned how to operate the lathe while making my first silencer, for a 300 whisper rifle. The silencer works well and I still use it.




Ranb

 

[Zak Smith]

............... Larger version of above photo.

Modern silencers do not touch the bullet, and are very effective at suppressing the muzzle report of the firearm. Some cogent explanations have been offered in this thread, including notably Riss'; however, there is more disinformation.

A standard mil-spec sound test measures the sound pressure one meter to the side of the muzzle (and a bunch of other specifics). Using this test, the best-in-class centerfire rifle suppressors reduce the report vs. a bare muzzle by approx 30-35 dB.

Some have said that while the sonic crack exists, suppression is pointless. This is far from the experience of most suppressor shooters. First of all, from the shooter's/spotter's point of view, the crack is not readily audible unless there is a physical structure (like a wall) to reflect it from downrange of the muzzle. For others in the area, there is no "BOOM" report, as many have mentioned. The sonic crack is typically only audible relatively close to the bullet path, and only in certain spatial relationships to the bullet path.

A suppressed AR-15 is still fairly loud for the shooter because so much noise "comes through" the action. On the other hand, a suppressed bolt gun (such as pictured) is pretty quiet from the shooter's perspective.

A setup like this literally goes "Pfft pfft pfft":


............... Larger version of above photo.


Another way to think about what Riss said in terms of surface area and heat is that a suppressor buffers the pressure, releasing it at a lower peak and average pressure but over a longer period of time.