SILENCER SATURDAY #77: Discreet Ballistics MASSIVE Metering Day

    Metering Day

    Hello everyone and welcome back to TFB’s Silencer Saturday, saving your hearing one weekend at a time since 2017. Last week we talked about the use of suppressors by criminals – a unicorn-sighting type event in comparison to all other violent crime in the United States. However the discussion was important, especially for uninitiated shooters who’s previous knowledge of suppressors might have strictly come from media and entertainment sources. Since last week, the American Suppressor Association has started a petition campaign as well as a membership drive to protect silencers from official scrutiny. Luckily, today we get to return to to actual suppressor data with the results from a massive metering day coordinated by ammunition manufacturer Discreet Ballistics.

    As a refresher, Discreet Ballistics hosted a similar event last year with some great data.

    Unboxing: YHM – Turbo K 5.56

    Hot off the shelf is the Yankee Hill Machine Turbo K 5.56. I’ve been anxiously awaiting the arrival of this little guy, but unfortunately I only had time for a few unboxing photos today. I’ll get some range time tomorrow and get you a first hand look this coming week.

    For supersonic rifle setups, I’ve always favored a smaller can over something larger that may drop a few few extra decibels. For me, the point of a 5.56 silencer on an SBR is a reduced footprint with enough decibel reduction to keep your ears from exploding.

    At sub $400 street prices, the Turbo K looks to be an awesome addition to the market. Stay tuned.

    Here are a few size comparison shots with the Delta P Design Brevis Ultra.

    Now, back to the metering day…

    SILENCER SATURDAY #77: Discreet Ballistics Massive Metering Day

    Due to day-job assignments, I was unable to attend the Discreet Ballistics metering day, which was extremely disappointing. Besides some of the best silencers, some of the best people in the silencer industry were on hand to share their knowledge and experience. While the U.S. suppressor industry can sometimes be known for it’s drama and conflict, the engineers behind these muffler designs are awesome. I’ll let David Stark, owner of Discreet Ballistics, describe the event in his own words.


    On June 8, 2019 Discreet Ballistics decided to spend a perfect 75 degree New Hampshire Saturday measuring the sound reduction of 36 silencers all shooting our 300BLK subsonic ammunition and 7 of these 36 were shot with supersonic 175gr 308WIN Federal Gold Medal Match. In addition to numerous representatives from silencer companies, we were lucky enough to be joined by a team from Brüel & Kjær as well as Erich Thalheimer a board certified acoustical engineer and former Brüel & Kjær employee. As some of you may know, the old standby for silencer testing is the venerable Brüel & Kjær 2209 which was last manufactured in the early 1970s. This analog instrument with its 20µs rise time is the current accepted standard for silencer sound reduction testing (Mil-1474D and Mil-1474E). Currently no hand held digital meter can come close to the accuracy achieved with the Brüel & Kjær 2209. We were fortunate enough to have Brüel & Kjær bring along some new hardware in the form of a semi field portable Pulse system which has gained the moniker “mini-Pulse”. So in the woods of New Hampshire we pitted two 40+ year old analog 2209s against a brand new digital mini-Pulse which had just received a fresh software update from engineers in Denmark to streamline its user interface. 

    To learn more about the new Brüel & Kjær and their important work to measure decibel levels of gunshots, check out their website here:

    Brüel & Kjær Mini Pulse 

    Metering Day – Host and ammunition supplier:

    Metering Day – Manufacturer participants:

    Metering Day – Industry Participants:


    Temperature and weight (with attachment device) of every silencer was recorded prior to shooting. Atmospheric conditions were recorded every two hours utilizing a Kestrel handheld weather station. A control silencer was shot to accompany the recording of atmospheric conditions to help account for any dB performance swings throughout the test day. A large LCD TV acted as a monitor for attendees to look at real time sound measurements.

    Metering Day

    Credit: Ryan Palmer

    Raw Data:

    1) Unsuppressed Baseline Ruger American Ranch 16″ using Discreet Ballistics 300BLK subsonic 16″ specific loadings (reduced powder charge)
    2) A 308WIN Ruger Gunsite Scout with a 16” barrel was used to test supersonic ammunition
    3) Asterisk (*) denotes the first reading(s) went beyond the 20dB range on the 2209 – mostly due to loud FRP (First Round Pop). Unfortunately the data collected by the mini-Pulse for these shots was not saved. 

    Note: The Dead Air Nomax is a prototype design that appears to be a longer Nomad.

    Credit: Ryan Palmer

    Credit: Ryan Palmer

    Wiped Silencers

    Supersonic .308 Testing

    Link to raw data:


    While there are many ways to evaluate and compare silencers, real data like the above list collected at the Discreet Ballistics metering event is a rare gem. Using two different meters, a standardized setup process and controlled variables like ammunition, environment and hosts provides great information for further evaluation. Beyond that, I’ll let these numbers speak for themselves.

    As a reminder, decibel meter numbers alone don’t tell the complete story on which to base your next purchase – Your needs and mission requirements should drive your decisions. But when we are talking about comparative data, this massive metering day is about as good as it gets. Thank you to everyone involved, especially Discreet Ballistics.

    Be safe everyone and we’ll see you next Saturday right here at TFB.

    Silencer Saturday is Sponsored by Yankee Hill Machine:


    Buy YHM silencers and accessories at:

    Silencer Shop – Hansohn BrOthers dead eye gun supply

    Mac tactical

    All YHM Products At Brownells

    DEALERS: If you want your link to buy YHM suppressors included in future Silencer Saturday posts, email: [email protected]

    Premiered 21 hours ago – Suppressed Nation

    On todays SuppressorShowdown we are looking to see how these cans stackup on an 11.5 factory Colt 556 upper! This has a standard a-frame gas block and a fullauto bcg. The results have been very tight in our other metering findings with 300bo and 308 but will the smaller bullet of a 223 show what can performs across the board?? Will the smaller bore of a 556 meter better then the 30 cal cans? Follow along and see the results!

    special Thanks: Mac Tactical


    Editor In Chief- TFB
    LE – Silencers – Science
    [email protected]