The Truth About Suppressors, Part 1 – How They Work and What They Really Do

silencerco suppressor silencer

Courtesy SilencerCo

By David Lewis

You can read part 2 here

This project is a comprehensive look at silencers with testing data that shows exactly what difference a suppressed firearm can make on sound levels while shooting.

Understanding How Firearm Silencers/Suppressors Work

When you fire ammunition from a gun, the ammo generates hot pressurized gases that need a place to escape.

As these turbulent gases exit the firearm, the dramatic change in pressure causes a loud blasting sound. A silencer’s job is to redirect these heated gases through a system of chambers and baffles to slow down, cool, and limit the pressure and noise emitted from a firearm’s barrel.

Jeremy S. for TTAG

One great example of how silencers work can be seen when looking at car’s muffler. A muffler’s job is to take the hot gases and noise generated from an internal combustion engine and slow them down through a system of tubes and baffles. The result comes out as exiting exhaust within an acceptable audio range.

Just like car mufflers, there is no one-size-fits-all solution for firearm silencers. They come in different shapes and sizes. This lets us control how loud or quiet we would like our firearm to sound.

Firearm silencers are so similar to car mufflers because the inventor, Hiram Percy Maxim, actually helped with a lot of the research for improving automobile and industrial silencers. His company, Maxim Silencers, is still running strong over 100 years later and remains a leader in the industrial noise control business.

Suppressor vs. Silencer

Silencers are continually a hot topic of debate between gun owners and gun control advocates. The debate usually starts when asking what exactly we should call these devices.

The term “silencer” is really a colloquial term for firearm suppressors, and one of the most misleading aspects of the whole debate. Contrary to the term, “silencers” do not completely silence a firearm.

Similar to the whole magazine vs. clip argument, there are staunch advocates in favor of never using the term “silencer” when discussing firearm suppressing devices. Many point to the way silencers are portrayed in the media as the basis of inaccurate representation of their capabilities.

When used in action films, the bad guys are usually running around gunning down their targets, all while remaining undetected due to the whisper like sound levels of their evil guns. While this makes for a great story-telling device, the real-world accuracy of how a silencer actually performs is much different than its Hollywood portrayal.

In reality, most civilian-accessible firearms emit sounds ranging from 140-175 decibels. Silencers only marginally suppress a gun blast, bringing those levels down to around 120-150dB. Most of the time, the sound is still very obviously identifiable as a gun shot.

Many gun owners also fear that inaccurate portrayals could lead to even more regulations for silencers/suppressing devices.

For what it’s worth, the ATF uses the term “silencer” in their yearly statistical update for sales and applications for firearms and other NFA items.

Oh, and Mr. Maxim, the inventor himself, called them silencers. So, in the suppressor vs. silencer debate we’re going to call them silencers out of respect to Mr. Maxim. But, know that we’re not advocating the Hollywood portrayal of these tools as accurate.

How Effective are Silencers?

When it comes to a silencer’s capabilities, there is a short and simple answer to the question, “How much quieter is a gun with a silencer?” The answer is, it depends.

There are many factors that go into how a suppressed gunshot will sound. They include the type of silencer used, firearm/caliber choice, and ammunition being fired. Even ambient temperature and atmospheric conditions can all impact the overall sound a firearm emits.

Silencers mainly focus on controlling the sound level emitted from firing a round of ammunition. But keep in mind, a firearm’s action also creates mechanical sounds when cycling rounds of ammunition. These sounds are in no way changed or reduced by the use of a silencer.

Caliber and Firearm Choice

Since silencers can be expensive and a hassle to purchase, many people opt for a model that will work well with multiple calibers. One popular choice is using a .30 caliber silencer used to shoot rounds such as .308/7.62 NATO, and 300 AAC BLK, but also using it to shoot smaller .223 and 5.56 NATO rounds.

Even though a .30 caliber silencer will suppress a gunshot from a smaller caliber, the sound isn’t as suppressed as it would if the shooter were using a model made specifically for the round being fired.

Barrel length can also have an effect on the overall sound levels of a gunshot.

Generally, the shorter the firearm barrel, the louder the blast will be. A longer barrel allows more time for the powders and gases to burn before escaping the end of the muzzle.

Nick Leghorn for TTAG

Subsonic vs Supersonic Ammo

Along with the sound of the action, there is an additional insuppressible noise that comes into play, but it has to do with the actual projectile itself.

Since the use of a silencer doesn’t alter the performance or velocity of the bullet being fired, when the projectile breaks the sound barrier you will hear what’s commonly known as a sonic boom or in this case, a sonic crack.

This audible confirmation of a high velocity projectile breaking the sound barrier can reach upwards of 150dB, a level that’s capable of rupturing eardrums.

Atmospheric conditions like humidity and temperature however do have an effect on the speed at which the sound barrier is broken. That speed usually falls in the range of 1,100 feet per second. Although, the warmer it gets, a greater velocity is needed to break the barrier.

For instance, the following chart identifies temperatures and the corresponding velocity at which the speed of sound is broken:

Most rifle ammunition is manufactured to produce supersonic speeds, although there are some exceptions. Pistol calibers on the other hand are usually a better choice to achieve speeds less than 1,100 feet per second, also known as “subsonic.”

It’s possible to shoot both subsonic and supersonic rounds through suppressed firearms. Just keep in mind that the sonic crack can in no way be altered or suppressed itself.

Benefits of Suppressing Firearms

Preserving Hearing Health

Even if you’re not an avid shooter or gun owner, it’s easy to understand one simple fact; exploding gunpowder is really loud. It also doesn’t take an audiologist to understand that constant exposure to loud noises can lead to hearing loss.

Hearing loss and tinnitus caused by overexposure to loud noises are two of the most common medical conditions for recreational shooters and hunters. In fact, WebMD claims hearing loss is the third most common health problem in the United States.

A decibel level chart with sound level descriptions

Courtesy ammotogo.com

The use of a silencer can reduce the deafening sound of gunfire for hunters and shooters by 30-40dB. This is comparable to benefits of using in- or over-the-ear hearing protection.

So why not just wear ear protection all the time? While we definitely recommend using hearing protection, every shooting situation is different and ear-pro may not always be an option.

For example, in a law enforcement shooting situation, an officer may not have time, nor the desire to worry about protecting their hearing. Safety and survival of the officer and innocent bystanders is the key concern.

Shooting in enclosed spaces, as in a potential home defense situation, can also lead to permanent hearing damage. The reverberations of a gunshot off of the surrounding walls and ceiling can amplify the blast, regardless of the firearm used.

“…the only potentially effective noise control method to reduce students’ or instructors’ noise exposure from gunfire is through the use of noise suppressors that can be attached to the end of the gun barrel.” – The Centers for Disease Control and Prevention (CDC)

Hunters typically don’t wear ear protection when out in the field, either. For starters, a hunter needs to be able to clearly listen for the game they’re after. They also need to have full situational awareness, with the ability to clearly communicate with other hunting companions. And in the case for using electronic hearing protection when hunting, most state laws forbid the use of electronic devices that aid in the locating of game animals.

Research that demonstrates the superiority of silencers over traditional ear protection has been published by Matthew P. Branch, MD. He found . . .

“All suppressors offered significantly greater noise reduction than ear-level protection, usually greater than 50% better. Noise reduction of all ear-level protectors is unable to reduce the impulse pressure below 140 dB for certain common firearms, an international standard for prevention of sensorineural hearing loss . . . Modern muzzle-level suppression is vastly superior to ear-level protection and the only available form of suppression capable of making certain sporting arms safe for hearing.”

Recoil Reduction and Accuracy

It’s natural to flinch in anticipation of loud sounds or movements. It’s in our genes. This is commonly experienced by many people when shooting a firearm.

If you’ve ever spent time at the range or in the field hunting, you probably noticed how your shoulder was somewhat tender the next day due to the recoil of the firearm. Anticipating this harsh recoil, shooters tend to brace for the impact and the blast of the muzzle just prior to pulling the trigger.

These additional small movements by the shooter can result in poor accuracy down range.

A man shooting an AR 15 rifle with a silencer

By redirecting and cooling the fired gases, silencers are beneficial in mitigating the overall recoil felt by the shooter. In return, the shooter can overcome the instinct to flinch and achieve better shot placement at the range and more humane kills when hunting.

Muzzle Flash Reduction

By using a silencer or suppressor, you can also greatly reduce, or in many cases eliminate the bright muzzle flash caused by the burning gases exiting the barrel.

The bright flash emitted from a gun blast can cause temporary blindness and disorientation of the shooter or others in close vicinity. This is typically only an issue when shooting in low light or night time settings, like during a home defense situation, or a night-time predator hunt.

Noise Complaints

People generally don’t like to be interrupted by unwanted noises. The same principle applies to shooting on personal property or rural gun ranges. Even on large tracts of land, noise ordinances can still come into play and neighboring properties may not want to hear you plinking away all afternoon.

Silencers can help soften these noises from personal and public ranges, as well as hunting properties. And a happy neighbor is well worth the investment, trust me.

 

In part two tomorrow, we’ll discuss the legality of suppressors, their popularity, and data showing just how effective they are in reducing damaging noise levels on different kinds of firearms. Stay tuned. 

This article originally appeared at ammotogo.com and is reprinted here with permission. 

comments

  1. avatar Leighton Cavendish says:

    I just wish it did not take so long for the background check…months to over a year in some cases. Even if you have previously purchased similar items and already have photos and fingerprints on file.
    Are they calling your Kindergarten teacher each time to see if you ate paste?
    Some places will let you use your purchase at their facilities while you wait for the tax stamp to come in.
    I think that’s a great idea. You already paid for the item

    1. avatar Scott C. says:

      Tell me about it, my can has been in ATF jail since October of last year.

    2. avatar Scott D. says:

      Just got my first one out of jail 4 days ago. 11 months to the day for approval. Just a couple days shy of a year from purchase until pick up. I’ve been shooting it on everything I can find this week. Makes a big difference. Two more suppressors currently going through the motions at Gov.co as we speak. If I was approved for one of them, you would think the other two would be approved too? Alas, we wait. Maybe an early Christmas present based on current wait times. Top tip: Get a Gun Trust!

      1. avatar Leighton Cavendish says:

        As I said…what kind of checks are they doing? And if you applied for multiple stamps, why does each take so long?
        Shouldn’t a check last for awhile?
        Are they doing the same checks for each and every item, each and every time?

        Maybe they need to make live-scan prints mandatory so they can do a fingerprint check more quickly.
        Maybe also a digital photo rather than actual passport photos.

        CBP does instant fingerprint and photo checks on people entering the country. Why can’t the ATF use a similar system?

  2. avatar Shire-man says:

    Anybody who has a suppressor should let as many people they can shoot with it.
    On paper a 30db reduction didnt seem worth it to me but in practice the difference is quite stark.
    At the same time anyone who thinks suppressors make for a whisper quiet Hollywood pffft will hear the truth.
    Suppressors are just very practical no-brainers for just about every kind of shooting one would do.
    In a sane world they’d be mandatory.

    1. avatar Eric in Oregon says:

      Re 30 db not seeming like much on paper, I thought the same thing until I realized that’s about the equivalent of wearing foamies.

      “In a sane world they’d be mandatory.”

      Amen to that.

    2. avatar BLAMMO!! says:

      They’re apparently not very useful in the commission of crimes. Otherwise, criminals would use them. And it’s not because criminals can’t get them. They could make them using materials from any hardware store. Or, a Fram oil filter.

  3. avatar Fully Involved says:

    Join the ASA! (Basically the GoA of suppressors)

  4. avatar GluteusMaximus says:

    I have an air rifle that propels the pellet supersonic and it makes the crack sound. The media is ignorant of how these things work

    1. avatar Marcia K Mason says:

      The media does not care to learn how things work. Their job is to be sensational and attract people to their byline. Even if it means lying. If only 1% of readers know the truth they’ve still amazed the 99% that don’t.

      1. avatar GluteusMaximus says:

        Correct

  5. avatar Knute(ken) says:

    What a well written article. No 2nd grade grammar or spelling errors, and more important, not a SINGLE gross error of fact to correct. Obviously not written by the TTAG staff. Only Dan Zimmerman can write at this level, but it isn’t his byline.

    1. avatar No one of consequence says:

      You missed the last line in the article giving the attribution.

      1. avatar Knute(ken) says:

        Yup, I sure did. It appears as though this ammotogo still has a writing standard higher than the second grade. If only TTAG would step up to the 5th grade level…
        Oh well. As my Dad used to say: “Shit in one hand and wish in the other. Note which hand fills up first”. TTAG has fallen, and it isn’t coming back.
        But ammoland now has a decent comment system, so others are picking up the slack, just as full30 and bitchute are now hosting those driven off by google and youtube. And perhaps now ammotogo as well. Glad to hear about any sites online that still have integrity, or that at least can write at a 5th grade level. TTAG now appears to enjoy being comparable to a Kindergarten class.

  6. avatar route66paul says:

    The only problem here is that if suppressors were legal for all, states would be making them mandatory on all guns.

    1. avatar Leighton Cavendish says:

      All guns would be integrally suppressed if they were invented today.

  7. avatar RIGHT TO HEAR UR GRANDKIDS says:

    https://www.instagram.com/2020americamatters/

    The right NOT to be Deaf for life SHALL NOT BE INFRINGED!!

    Fire a gun inside a home without a suppressor will lead to hearing loss or complete deafness blowing our ur eardrums…

    Suppressors are hearing safety devices for man and beast.

  8. avatar Alan says:

    As to complaints, regarding the noise of gun fire, from residential areas, housing tracts and the like, which was there first is a question that has long struck me as more than a little interesting. What would happen if shooting ranges filed complaints about traffic problems obviously caused by housing developments. The question seems as broad as it is long seems appropriate.

  9. avatar M1Lou says:

    I have two cans in jail right now. The wait sucks as I already own two other cans. Like I have said in previous posts, if it were easier to acquire, all of my modern rifles would have their own can. It makes that much a difference in the shooting experience. For someone who already has hearing damage, it is nice being able to drop to single ear pro. I also knocked my ear pro slightly from recoil firing 6.5 Creedmoor breaking the seal and allowing sound into my right ear.. Luckily the blast and report wasn’t at maximum, but it was still very uncomfortable.

  10. avatar Anymouse says:

    Silencer v. suppressor isn’t like clip v. magazine. I can point you to an M16/AR15 removable box magazine and the 10 round stripper clip that loads it. Or, the M1 Garand enbloc clip and the non-removable magazine in the rifle that it fits in. The two are very different things. Similarly, unless it’s a muzzle loader, you load rounds or cartridges into a gun, not bullets (a component of the cartridge, along with case, powder, and primer). They may be colloquially the same, but they are different technically.

    I defy you to show me a suppressor that isn’t a silencer, or vice versa. They’re synonyms, as are the less common muffler, sound moderator, sound attenuator, noise moderator, or noise attenuator.

    1. avatar Leighton Cavendish says:

      But the word silencer implies silence…a lack of sound altogether…and that is far from true for most affordable suppressors.
      There may be limited-used, very expensive true “silencers” out there…but I have never seen one for sale to the public…even with all the NFA hoops one has to go through. Maybe for the CIA and NSA secret squirrels…but not for the mere peons.

      1. avatar Anymouse says:

        It doesn’t matter what you think the name implies. The inventor chose that name, and that’s the legal name. “Suppress” implies preventing or ending, often with force, like suppressing a rebellion or dissent. That’s not accurate either. Use attenuator if you want to be accurate. That’s why the ratings are in decibels.

  11. I’ve been using the term “gun muffler” for quite a while. It’s accurate and instantly understandable. POTG who are all too familiar with the silencer vs. suppressor griping simply smile and nod. Others (non-POTG) who hear me say that don’t even question it.

    1. avatar Knute(ken) says:

      Good call. I am so stealing that…. But I’ll give you the credit.

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