One of the biggest topics in the gun world recently has been suppressors and the prospects for passage of bills that would deregulate them like the Hearing Protection Act and the SHUSH Act. For those who haven’t followed the news, the HPA would remove suppressors – a.k.a. “silencers” – from the list of heavily regulated devices, allowing them to be purchased like a firearm, but without a tax stamp from the ATF. The SHUSH Act would allow them to be sold over the counter like any other firearm accessory.

Suppressors are the reason a number of gun owners have threaded barrels for their pistols, whether the threaded barrel goes in their concealed carry holster or not.

But how well do suppressors really work? It’s worth looking at, as the only experience most people have with a suppressor is when they’ve seen one in a movie.

The typical gunshot produces 140 to 160 decibels of noise. Any noise above 140 dB can produce instant hearing damage, so anything that brings a gunshot below that threshold is worth looking into.

It’s a myth that suppressors make any firearm “silent.” A gunshot is still going to sound like a gunshot; it’s just going to be somewhat quieter. That said, how much quieter?

The truth is there’s an economy of scale. Part of the noise attenuation comes down to the suppressor used. Is it designed for the caliber you’re using or is it more of a generic design intended for multiple calibers? How long/short is the suppressor and how is it made? Those factors make an impact on the noise reduction you’ll experience.

So does the ammunition you use. Supersonic ammunition — anything traveling at 1,125 feet per second and faster — makes a sonic “crack” when it breaks the sound barrier that subsonic ammo doesn’t. Ambient temperature, humidity and elevation also make an impact.

Put a bit more simply, how well a suppressor works on paper can and will differ from how well it will work for you depending on a number of factors, so your mileage may vary.

That said, let’s try to come up with an average noise reduction estimate of sorts.

Looking at a few different products, SilencerCo says their suppressors reduce the sound pressure of a 9mm gunshot to anywhere from 125.7 dB to 131.5 dB, depending on the model. Advanced Armament Co, another popular supplier, claims a 23 dB to 33dB reduction or down to about 127 dB. Liberty Suppressors says their cans reduce the sound of a gun shot from 24 dB to 38 dB, depending on model and other factors as above.

In short, we can presume something on the order of 30dB of attenuation as an average. Since the typical 9mm gunshot produces about 160 dB of noise, that means a suppressor will lower the boom to about 130 dB. It could be more or less – even much less, in some cases – but that’s a reasonable average. You can argue amongst yourselves in the comments if you take umbrage.

Assuming an average noise reduction of 30 dB and a sound level of 130 dB with a suppressor, you’ll still want to wear ear protection. Your fellow shooters and neighbors in the area will appreciate the relative quiet, but you’ll still need to protect your ears.

The louder the noise and the more you’re exposed to a noise level, the more likely hearing damage becomes. Hearing loss can be induced by being exposed to a constant 85 dB noise, which is why OSHA mandates 85 dB be as loud as workplaces get – even industrial ones – without mandatory ear protection.

Noises in excess of 120 dB – which is the sound pressure generated by a jumbo jet on tarmac from 100 yards away – can cause permanent hearing loss if exposure lasts just minutes. Fifteen minutes listening to a 115 dB sound system will probably damage your hearing. An afternoon’s shooting, even if attenuated by a suppressor to that lower level, can still damage your hearing permanently.

To sum up, suppressors don’t “silence” a gun shot by any means. Though they can be very effective and definitely reduce overall noise levels, they still generate – in most cases – sufficient noise to damage your hearing. Thus, if you’re one of the growing number of gun owners who are buying suppressors these days, or plan to if they’re de-regulated, make sure you use it with hearing protection.

 

Sam Hoober is a contributing editor at Alien Gear Holsters and Bigfoot Gun Belts. He also contributes regularly to Ammoland, Daily Caller and USA Carry.

 

43 Responses to How Well Do Suppressors Actually Work?

  1. There is at least one video on YouTube that compares the sound from a rifle with and without a suppressor. It’s surprising how much the supersonic bullet contributes to the overall sound level.

    If HPA passes, I expect suppressors to become ubiquitous. For the shooter, it means ear plugs or muff but not both. For neighbors close to outdoor ranges, it means a substantial reduction in noise pollution.

    • HPA can’t pass, if it does then neighbors that built their house 2 years ago backing up to an outdoor range won’t have an excuse to shut down the 80 year old range.

  2. I agree should be 1125 Feet per Second. I even did the conversion to check to see if article had converted to MPH.

  3. Write to your congress critters.

    The NFA is a narrowly applied tax, and it takes 6-8 months (average – current wait times are 1 year-ish; I know, my 9th tax stamp just came back).

    What other right has a narrowly applied tax OR is delayed (the reason for delay is immaterial)? NFA items get BOTH!

    Why this isn’t a slam dunk to rule NFA unconstitutional in the first place is beyond me. At least get items removed from NFA – it’s a START…

    • The constitution says you have the right to keep and bear arms, it doesn’t address silencers/suppressors or other accessories.

      • Don’t worry I won’t tell the man that you aren’t petitioning the gov for regress of grievances nor are you using a press to produce your post.

      • @ Mattster

        True enough. But the Constitution does not give the federal government the authority to regulate such items either.

      • The 2A applies to ammo and magazines as well. Not just guns. There have been court cases providing evidence to such. Hence, the stay on the mag law in CA. Accessories apply just as much as the guns.

      • What about integrally suppressed arms? What about arms like Sig’s early MPX prototypes with integral muzzle brakes with ZERO noise attenuating properties? Arguing that the 2nd doesn’t cover ‘accessories’ is akin to saying the 2nd doesn’t protect ammunition, or magazines essential to the function of said ‘arms’.

  4. “Advanced Armament Co, another popular supplier, claims a 23 dB to 33dB reduction or down to about 127 dB”.

    earplugs are 27-30 dB reduction. so, a suppressor is as good as putting in earplugs?

    • Earplugs may not give equivalent noise reduction simply because of bone conduction. Yer noggin is a pretty large sounding board that will pick up that unrestrained 160dB. No, it’s not even close to the effect of an open ear canal, but it’s something to consider.

  5. I actually like the inertia that my 5.4oz suppressor puts at the end of my Five Seven barrel. It goes along way to mitigating “Don Knotts hands”. My 5.7 loads with VV N105 are ridiculously loud without it.

    • Do you hand load the 5.7? If so, can you share a recipe? I’m gathering you use N105 powder. Any particular powder weight/bullets/case length/COL?

      I’ve been thinking about hand loading for it, but it’s hard to find any data that I trust. Apparently I trust you because I’ve seen you comment here a bunch of times. Really crappy logic, but there it is.

  6. On that note… for the love of all that is sacred, can we please get HPA/SHARE/SHUSH on the floor already? I know it’s Congress, but I feel like this thing should have more momentum than it seems to have.

  7. For Defense you should allways use heavy subsonics, no point of have an suppressor ore not !
    Hunting is another case, when you need distance over 150 meter you must drop the subsonics as option …………

  8. Suppressors work at least as well as the muffler on your car, with the added benefit that, unlike your car’s muffler, suppressors don’t totally wreck your gas mileage (for the stupid POS greenie weenies out there).

  9. Unfortunately the GOP knows they have you over a barrel, so they’re not going to pass jack. Suppressors are nice I still like to wear hearing protection and I prefer muzzle breaks since a good one will reduce the recoil more than a suppressor will. It’s easier to see shots with a brake.

  10. My suppressed PS90, with subsonic ammunition is still kind of loud. It’s worth noting I have had one FTF with SB193 on that platform (I’m not the one firing it in the video):

    https://www.youtube.com/watch?v=H0drZh_fGWE

    However, using subsonic .22 rounds, out of a Tactical Solutions rifle and my Dead Air Mask? Crazy quiet!!!

  11. I have been urging TTAG for awhile to get a widget that measures decibels and test a bunch of suppressors, ammo, guns, and more specifically those other “factors”. It would be great to compare some (relatively) quiet unsuppressed firearms against ones that are. Yes, I know all that would cost some money but you could get several articles out of it.

    • Honestly, I would have thought that at least one suppressor manufacturer would have donated one – in return for a little product endorsement…

      • Well, that’s because you aren’t an audio engineer and don’t realize how bloody hard it is to measure really loud impulse noise.

        It’s really, really hard– you see poorly done “measurements” all the time on the interwebs– everyone I’ve seen it garbage.

        And the silencer makers know this.

  12. I load up a 55gr lfn-gc .224 under 2 grains of trailboss for a velocity of 1040fps in a 16″ barrel and it is “Hollywood” quite but what the left doesn’t understand is that to get the quite they think happens with suppressors the cartridge is downloaded to the point it’s nowhere near as powerful, I have an air rifle that is more powerful than the aforementioned load

    • Sounds like my 308 sub rounds that I load with 210gr projectiles. They aren’t worthless, but really I don’t think I’d even try for a small antelope with that. Maybe it would work and maybe not. Moral of the story is that what they don’t understand is quiet quiet rounds have a built-in piece to the equation and that’s speed. Go over that speed and you will never be even close to the Hollywood quiet. Single shot firearms with subs get you pretty close in some situations, but not like they think.

    • My 5.56 subs are with Hornady Match 75gr. BTHP with 4.8gr. of Trail Boss.
      About 1080 FPS.
      My 300BLK subs are Hornady Match 208gr. BTHP with 8.5gr. of H110
      About 1070 FPS.

  13. Even when we wear ear pro, if we are not also using a suppressor, we are damaging our ears every time we go shooting. Sad but true. The question is, how clinically significant will the loss be over the many decades.

  14. Even when we wear ear pro, if we are not also using a suppressor, we are damaging our ears every time we go shooting. Sad but true. The question is, how clinically significant will the loss be over the many decades.

  15. It might be helpful to note that the decibel scale is logarithmic: Every 10 decibel reduction is a halving of perceived volume, so a reduction of 25-35 decibels is a larger reduction than you might think.

  16. Why are we not calling them ” gun mufflers?”
    Everyone knows a car needs a muffler or it bothers everyone in the street
    Yet a car with a muffler is not silent

  17. I’ve found that mentioning dB numbers is meaningless with the general public. Too hard to comprehend what a logarithmic scale really means in the real world. A person truly needs to be exposed to an unsuppressed gunshot first, and then put the silencer on. Nothing too harmful, just a 22LR shot outdoors.

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