SBR Noise Comparison

Due to the limited capabilities of the meter used for testing, as well as the sloppy testing protocol, I have removed the contents from this page and hidden the video on YouTube.

I am working with a suppressor manufacturer here in Minnesota to re-test these firearms with their professional (and very expensive) equipment.

Thank you to everyone who expressed interest in the post and the concerns about the testing. I feel like due to the metering and the test methodology the information may not even be useful enough to be “directional” in comparing the relative loudness of the tested guns.

About the Author:

Short Barrel Shepherd Short Barrel Shepherd is a regular guy and works to make Web sites and mobile apps easier for people to use. He spends his free time attending fight-focused firearm, knife, and combatives training, motorcycling, writing, and playing games. His daily carry is a Glock 19 pistol and an AR15 .300 Blackout pistol in a backpack.
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13 Comments on "SBR Noise Comparison"

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  1. David says:

    I’m not surprised about the .300AAC gun being the quietest; don’t most loads use fast-burning powder?

    As for the rest of it, comp/brake louder than flash hiders, I suppose.

    • Short Barrel Shepherd Short Barrel Shepherd says:

      Hi David, you are correct about the fast burning magnum pistol powder frequently used in 300 handloading. After putting about 500 rounds through it and listening to the comments about its noise I expected the results to be different. I wish there was a way to measure concussion easily.

      • David says:

        I’ve always thought a Ferfrans CRD setup would be very nice on 7.5″ AR builds. You are very correct that noise is really less of a problem than concussion.

  2. J.C. says:

    I would be interested in seeing what the readings at/near the muzzle would be. And I wish I could bring my suppressor with to test it out at some point.

    • Short Barrel Shepherd Short Barrel Shepherd says:

      I know. I wish that I had thought about a safe way to get the sound meter closer to the muzzle beforehand. Maybe next time.

  3. A-Game says:

    I would recommend mil spec testing. It makes it comparable to others testing the variable being the actual sound meter. Also use factory loads and document each load used in each weapon. Use the same 7.62×39 load, the same 5.56 load, and the same 300 Blackout. Your numbers don’t make sense. AAC published Remington 220 grn out of the 762sdn6 at 126 Db.

    • Short Barrel Shepherd Short Barrel Shepherd says:

      Hi there — we used the same ammunition in every .223 caliber weapon and every 7.62×39 weapon (Wolf across the board). The only handload was my .300, as I don’t own any commercially made .300 ammunition.

      I agree with the numbers being low, which is why I tried to call that out in the article as well as in the video.

      What I don’t think would change is the variance between the different weapons. I expect the Mini Draco to still be the loudest, with a 10 dB difference between it and the .300 AR15 pistol. However, I could be wrong. 🙂

    • A-Game says:

      I do believe this was an excellent way to determine the difference in Db roughly between the different rifles. Decibel scale is algorithm based and not linear. Every 10 Db the sound levels double.

  4. JRC says:

    Nice review of your process. I’m also glad you admit that you aren’t tying to claim scientific accuracy, which shows humility.

    To help your study if you repeat, sound meters have different settings. Mostly, the control how the meter averages the sound overt time, with many set to weight C and slow. Weight affects the frequencies that it is listening to. Slow means that they are averaging over longer periods. I think OSHA had some reconendations for mrasuring impact decils, which is similar operating firearms.

    Otherwise, good job.

  5. SV says:

    These readings definitely dont have any credibility as far as db’s go. They are, admittedly, okay for comparison but just “okay”. OSHA rates 140db as an acceptable ‘impact volume’ for someone without ear protection and requires ear protection if a worker is exposed to a time-weighted average volume of 85db or higher over an 8-hour shift (that would mean OSHA says your hearing will be fine if you shot that 6.75″ .300 all day long with no ear pro (if the meter was accurate))… Furthermore those numbers, if accurate, would be incredible to attain with suppressors. “Some people arent so keen on decibels” (I literally LOL’d)

    Basically what I’m saying is that your sound meter is way way off but I appreciate the effort and attempt to measure variances, however publishing such inaccurate numbers will cause confusion to many people who remember your db readings and are then confronted with accurate numbers.

    • Short Barrel Shepherd Short Barrel Shepherd says:

      Hi there! Thanks for the comment. We’ve gotten a lot of good constructive feedback about this article / video, and are exploring ways to do this again.

      Do you have any recommendations on meters? We’re trying to find / rent some quality ones, since it doesn’t make a lot of sense for us to buy expensive professional gear for a single video.

  6. Dan says:

    You meter is not remotely adequate for this kind of testing. It’s not even “close enough” to get a rough idea. Every one of those shots should have maxed it out or come close to it. Your meter showed them all being about as loud as a high school cafeteria. How many people do you think have permanent hearing damage from eating in a high school cafeteria without hearing protection? Your meter lacks the range and sample rate to measure a gunshot with any kind of precision.

    You can’t weigh a gorilla on a bathroom scale. You can measure the length of a flea with a ruler. You can’t check the temperature of a roasted turkey with an oral thermometer. You can’t measure a gunshot with a SPL meter that peaks at 140dB and samples at a rate slower than the duration of a gun shot. Period.

    • Short Barrel Shepherd Short Barrel Shepherd says:

      I totally agree. I am working with a suppressor manufacturer here in Minnesota to re-test these firearms with their meters.

      In the meantime, I have unlinked the video and edited the content of the post until further notice.

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