Meter Week: Rimfire

Welcome to our latest blog series on METER WEEK! We recently acquired a B&K 2209 sound meter allowing us to gather better sound data on our firearm hosts & suppressors. Traditionally at Creative Arms we’ve sent off our suppressors for evaluation and testing by 3rd party individuals or companies. This often led to long lead times on development and never really gave us the ability to see our suppressors compared to others in the industry all in one data set.

In this blog series we will be looking at the data we’ve gathered over a 3-day period with a variety of suppressors, host firearms and ammunition. Along with the data I will also be noting some subjective notes and personal experiences of what each suppressor sounded like in tone vs noise. When it comes to choosing the suppressor best suited for your usage you should consider the host firearm, application of the host firearm and suppressor (heavy use, single shot hunting, etc.), overall sound suppression, potential back pressure introduced into the firearm from the suppressor, overall tone of the report, weight, and if you’re really into it, sexiness & aesthetics of the design.

How we test

Standards

To begin, we first should discuss the standards of testing. For our testing we will use the MIL-STD-1474D standard. This standard is used by the military to measure the potential hearing damage from noise. This is the industry-accepted standard for testing suppressors as well. This standard calls for the sound meter to be placed one meter to the left and level with the muzzle, with the microphone oriented in an upward position. The meter is then placed 1.6 meters off the ground. To simplify this we use two tripods, one to hold the meter in location and one to give the shooter an exact point to hold the muzzle of the firearm. Note, that in the industry there is some debate on if the end of the barrel is the designated meter location or if the end of the suppressor is the designated location. In our testing we use the end of the suppressor. The firing order will start with the at-muzzle location, 5 rds unsuppressed, then 5 rds at-ear unsuppressed followed by 5 rounds at each location with each suppressor.

At Ear Data

Additional to the muzzle data we opted to also test the sound at the shooters ear. This measurement is taken at the same 1.6 meters in height and approx. 5-6”to the left of the shooters ear. Again, in the industry there is some debate on if this measurement should be taken to the left or right of the shooter as the action of the firearm and expelling gasses could be a variable. In our testing we have placed the meter to the left side as we wanted minimal action noise. Lastly, we catalogued the sound of the action from shooters ear and noted it in our data.

Firing Sequence

In our data set we will be looking at a 5 shot test group with the final number shown being the average of the 5 shots. These are loaded into the magazine 5 rounds at a time and fired in 5-6 second succession as we relay the data to the note taker. It should be noted that traditionally the first round in this data set will be higher (this is referred to FRP or First Round Pop) and the potential for the last round on autoloading (semi auto) firearms to be an outlier in the data is higher due to the bolt locking back on the last round. In some testing throughout the industry, you will see 6 rounds fired and the 6th shot being noted as a potential throw away number for the average.

Potential Variables

In suppressor testing, meter data can be affected by host firearms, barrel length, ammunition, temperature, barometric pressure, and elevation. We have gathered our weather data from the Des Moines airport which is just a few miles away from our private range. On all three days of testing wind speeds were near 0 mph in an open-air environment.

Other Testing Notes

The decibel (dB) is a logarithmic unit used to measure sound level. It should be considered that these data points do not represent the pitch or frequency of the firearm report. I will be noting any personal auditory experiences in regard to pitch (lower or higher pitch) where I can when discussing the data. If you want to learn more on quantifying sound this is a great resource to learn and understand DBs on a deeper level: https://www.animations.physics.unsw.edu.au/jw/dB.htm

 

Creative Arms Understanding Sound infographic

Before We Dive In

Before we dive into the data I want to explain that with rimfire data we are dealing with ranges of 1-3 dB, these ranges are most often not discernible by the human ear. I want to reiterate that these data sets can changes depending on a variety of variables. Above we have included a small infographic showing examples in each dB range.

Let’s get to the data!

So, we’re back from our first range day and things are looking great! Today was a perfect day to be out at the range, it rained yesterday and brought down the temp to 78 degrees, 54% humidity, 30.15 in barometric pressure and 0-1mph winds.

Today we are really getting our feet wet into private meter testing. The B&K 2209 has recently been calibrated from the previous owner and our control data//suppressors are matching up .2-.3 db to other public data with the same meter and condenser microphone. This week we will be looking specifically at our rimfire data. This includes .22lr Supersonic, .22LR Subsonic and .17HMR supersonic on a variety of hosts. The host firearms we are testing include a ruger 10/22 semi-automatic with a 16” barrel, ruger 22/45 pistol, Chiappa lil badger break action single shot 16” rifle and ruger .17HMR bolt action 16” rifle.

 


Our first data set we will be looking at is from our Ruger 10/22 Rifle with Remington .22lr Golden bullet. This ammo is commonly found on the shelf at your local gun store in 500rd boxes and has a marketed velocity of 1280FPS pushing it into the supersonic category. This ammo is a 36gr. projectile and consistent when it came to testing. Following that we will be looking at the same rifle data but with subsonic ammo from Federal American Eagle with a 45 gr. Projectile and marketed at 960FPS.

 

If this is your first time looking at any type of meter data, it is important to remember that these numbers are really dealing with sound pressure not necessarily what the report “sounds” like. In our first tests I was surprised with the results, specifically with our QB series 22 suppressor. This suppressor seems to do extremely well on 16” barrels. With supersonic ammo It’s 5 shot average was a 123.78 dB at the muzzle and 122.16 dB at the ear, while it averaged 118.4 dB at the muzzle and 123.96 at the ear with subsonic ammo. This lower average on the supersonic rounds I’m speculating to its K-cup style internal structure…backing this idea up is the fact that the Dead Air Mask has a similar cone design and provides similar performance on supersonic ammo.

Subjective observations: This being our first back-to-back testing with all the suppressors together there was a noticeable deeper tone difference in the Creative Arms Lil’ Guy, DA mask, Rugged Oculus over the QB series and SiCo Sparrow that made it easier on the ear. You still have the bullet breaking the sound barrier down range and causing a higher pitch crack but is still very manageable to shoot without other hearing protection aids.

QB Series .22lr Suppressor

Looking at this data set we can see some significant trends. Firstly, the infamous “First Round Pop” is evident in all of the suppressors tested on the 22/45, including the Rugged Oculus which is advertised as “No First Round Pop” however, it is minimal. The next evident trend is how much more suppression the Lil Guys, DA Mask, Rugged Oculus have compared to the QB Series 22 and SICO sparrow. These two suppressors seem to do best on 16” barreled firearms and suppressing higher velocity rounds.

The Lil Guy really flexed some muscles on the 22/45, having an average of 125.8dB at the muzzle and 122.06dB at the ear with supersonic ammo while touting 117.42dB avg. at the muzzle and 113.52dB avg. at the ear with subsonic ammo beating the next best by nearly 4dB difference. This average had a total dB reduction of nearly 38dB from the unsuppressed muzzle average of 155.2dB.

Subjective Observation:

I absolutely love shooting 22lr handguns with suppressors, it really gives you the chance to really experience suppressors do the work they were designed for. The Rugged Oculus and Lil Guy sounded impressively quieter compared to the other suppressors we tested. This was a nod your head in approval type of difference. The QB suppressor was noticeably louder in both pitch and overall volume//pressure, with the SiCo sparrow running a few dB behind it. I think this is really a good spot to stop and talk about how understanding what type of firearm you primarily are going to be shooting matters. As you see from the 10/22 data the QB series and SiCo Sparrow do great on the longer barrels (you’ll see more of this trend below with the Chiappa little badger) but are not the greatest on handguns. A lot of this has to do with the suppressor design and how it captures low vs high pressure gases. In a week or two when we discuss our rifle data, you’ll see some of the same type of changes between supersonic / subsonic suppression with different types of suppressor designs also.

Let’s move on to some subsonic ammo!

This data follows similar trends as the supersonic data, that being the Lil Guy and DA mask doing extremely well while the QB Series and SICO Sparrow tend to have higher results. Again, the Lil Guy absolutely shines on handguns, we have not collected data on our Volquartsen mini mamba yet, but I wouldn’t be surprised to see even lower averages on the DA Mask and Lil Guy with it. Dropping down to a 117.42dB average at the muzzle and 113.52dB average at the ear the Lil Guy crushed the at ear data, while being within a single dB of the Dead Air Mask. Enough on the pistol data. Time to hop into the break action 22 and .17HMR to wrap up this week’s data.

Lil’ Guy 22 Suppressor

Looking to this data set we had some major outliers in the data on shot 4 for the QB and Rugged oculus. I’m going to speculate that these drops in data were most likely due to ammo inconsistency and slowing down into the subsonic speed range. With that said if you were to take the shot 4 data point out of the at muzzle average, they both would have been in the high 124 db range with many of the suppressors. That said, the SiCo sparrow performed slightly better than the rest coming in at 122.1dB at the muzzle, while the QB series performed second best at the muzzle with a 123.38 dB average. Moving to the at ear we can see a higher spike on shot 5 in four of the suppressors. Again, the QB series outperformed the rest of the test group by nearly 3dB on the 16” barrel.

Time for one last look at some subsonic data. Both the DA Mask and QB series produced some good numbers, however they both suffered from major peaks and valleys in their data. I wish we could have reshot these to get another data set but that’s how testing goes. If you were to eliminate both their highs and low shots, they would have bumped up into the high 116s. Again, a thing to remember is were looking at a data set that is all within nearly 3 dB of each other. To the untrained ear you’re not going to be able to discern the difference between those. As we move to the at ear data the QB Series averages out at 119.5dB at the ear while the Lil guy averages out at 121.16 dB. Each suppressor tested had a high second shot.

Subjective Observation:

The Chiappa Little Badger is an absolute blast to shoot with any suppressor. With it being a break action firearm it’s a great introduction to new shooters both young and old. Being suppressed you’re effectively hearing the hammer drop at the shooters ear and really practice marksmanship with it being a single shot platform. To be honest all of the suppressors on this host platform sounded great, but the tone on the Lil Guy and the Rugged Oculus was deeper and led itself to a “quieter sounding” report.

One last data set to go! This one was really for our own knowledge. When we designed both the Lil Guy and QB series suppressor our market focused on .22lr supers and subs, knowing that these suppressors would work on the .17hmr, but would not necessarily be the best suppressor to do the job. Regardless looking at the data we can see that the at ear for all the suppressor’s average between 128.8dB-132.6dB. This range in sound is still spicy but manageable.

Subjective Observation:

.17hmr is not necessarily something that I shoot all the time, but utilizing any suppressor took the piercing sound out of the report. I think that if you are looking for a dedicated .17hmr suppressor to really consider something in a larger diameter to increase the overall suppression. Out of interest we took our 9mm tube diameter and internals and drilled a bore size for the .17 and were able to achieve a 126dB average at ear.

Wrap Up:

I hope that this post has helped you as a consumer better understand the differences in suppressor designs Creative Arms offer as well as give you a behind the scenes look at the testing, design and development that goes into suppressor design. Next week we will be looking at the pistol caliber data we collected on our Glock 19, MP5 Clone with trilug, Ruger PC Charger, 1911, and Vector SBR.

If you have any questions, feel free to email us at sales@creativearms.com and we will get back to you as soon as possible.

1 Comment

  • Dennis Marrero
    Posted August 19, 2022 2:41 am

    Great info. Can’t wait to get my QB 22lr titanium out of jail.

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