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Author Topic: A hearing safe X95.  (Read 1392 times)
Potss
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« on: October 23, 2017, 01:32:06 PM »

According to MAC's testing the .300blk X95 with a properly set gas block using supersonic ammo is hearing safe with a Q Half Nelson suppressor: https://www.youtube.com/watch?v=An9SUPk2IeE

Impressive setup considering Silencershop showed with the 5.56 suppressors it wasn't hearing safe.  Would like to see testing with the Q Half Nelson on a 5.56 X95 to see if it is more the can or the rifle.
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Leonitus
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« Reply #1 on: October 23, 2017, 03:34:06 PM »

Its all about the ammo in this case.
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Potss
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« Reply #2 on: October 23, 2017, 03:56:12 PM »

I'm not sure why that would make any sense, that is supersonic .300blk, not subsonic.  The difference between supersonic .300blk and 5.56/.223 is minimal.
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RabbitSlayer
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« Reply #3 on: October 23, 2017, 07:39:48 PM »

I like MAC, Tim is a great guy... But if he is claiming any supersonic bullet is hearing safe, he is wrong.  Come on Tim, you know this, and you should probably edit your video so you don't spread misinformation.
See my attached photo below.

Any sound produced by an object breaking the sound barrier is not safe for the human ear, it can/will cause damage to the human ear.  I would presume that any measured report of any supersonic crack being hearing safe as not properly measured.  Subsonic can be hearing safe, supersonic can not.

Any of you who have had a supersonic bullet fly over your head past 100 yards without earpro will know what I'm talking about, that sonic crack is really freeeking loud.



Source, Science.
https://en.wikipedia.org/wiki/Sonic_boom

(ETA)  I have had a bullet fired from a suppressed rifle fly over my head in a trench past 100 yards, There was no loud boom from the rifle, but the bullet flying over my head produced such a loud hypersonic ''Crack'' from the bullet traveling past the sound barrier, that it caused pain in my ears, and made my ears ring.  It was not hearing safe.
People might not notice the pain so much behind the gun because most of us have shot a lot without ear pro, but just because shooting with a suppressor doesn't hurt your ears as bad as without a can does not mean it is safe, you are still exposing your ears to NOT safe sound levels when shooting without ear protection using ammo that travels above the sound barrier.

Just keeping it real here.

NASA is currently trying to develop technology to alleviate the noise problems associated with breaking the sound barrier in aircraft, but still has not attained such performance for civilian aircraft.  If NASA can't do this right now, I highly doubt a suppressor company with a fraction of the budget of NASA is surpassing NASA in technology regarding alleviating the concussion of sonic boom.

https://www.nasa.gov/aero/centers_tackle_sonic_boom.html



* bulnoise.GIF (10.25 KB, 676x432 - viewed 51 times.)
« Last Edit: October 23, 2017, 08:00:44 PM by RabbitSlayer » Logged

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Leonitus
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« Reply #4 on: October 23, 2017, 07:56:29 PM »

Like Rabbit stated.......I canít see supersonic with a can being hearing safe
Gotta be sub-sonic
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Rastoff
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« Reply #5 on: October 23, 2017, 10:22:34 PM »

I don't agree. I've stood next to a .308Win that was shooting rounds that were 2,650FPS. He had a suppressor and it wasn't loud at all. There was a crack as it broke the sound barrier, but it was definitely hearing safe.

I'm not an expert on suppressors nor have I done a lot of research. This is just personal experience. Since it could be done on a .308Win, it should work on a .223Rem, no?
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RabbitSlayer
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« Reply #6 on: October 24, 2017, 04:19:15 AM »

I don't agree. I've stood next to a .308Win that was shooting rounds that were 2,650FPS. He had a suppressor and it wasn't loud at all. There was a crack as it broke the sound barrier, but it was definitely hearing safe.

I'm not an expert on suppressors nor have I done a lot of research. This is just personal experience. Since it could be done on a .308Win, it should work on a .223Rem, no?

The crack is the sound barrier being broken, which is not "hearing safe"  see my last comment.
It is well known hypersonic velocity is not hearing safe, research it on suppressor forums.





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RabbitSlayer
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« Reply #7 on: October 24, 2017, 04:25:14 AM »

You might not notice it, but certain frequency ranges will be dramatically damaged. 
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« Reply #8 on: October 24, 2017, 05:38:50 AM »

I've been in the pits at the National Matches and no way the crack of the supersonic bullets going overhead are hearing safe. 200 yards away from the muzzle blast on the far side of a earth berm. These are .30-06 from a Garand.

I also suspect a problem with measurement equipment and/or technique.

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RabbitSlayer
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« Reply #9 on: October 24, 2017, 07:03:02 AM »

Tinnitus really sucks..  Don't play stupid games.

https://www.google.com/search?q=tinnitus&oq=tinnitus&aqs=chrome..69i57.2333j0j4&client=ms-android-verizon&sourceid=chrome-mobile&ie=UTF-8#scso=uid_We8jMgAIDNoKY_oFZwOMaw_7:0













https://science.howstuffworks.com/question124.htm


http://dangerousdecibels.org/education/information-center/decibel-exposure-time-guidelines/



http://www.noisehelp.com/noise-dose.html



« Last Edit: October 24, 2017, 07:28:50 AM by RabbitSlayer » Logged

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Potss
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« Reply #10 on: October 24, 2017, 01:01:47 PM »

Ok some very misleading and incorrect comments in here.

1.) Yes all supersonic rounds will have a crack at about 150db or so.  However this occurs far enough away from the shooter that it DOESN'T EFFECT THE SHOOTER.  You have to be down range for this to be a problem.  Beyond just physics, remember the meter in any given suppressor video (including this one) would pick it up.  So no, you are 100% wrong about supersonic ammo and noise to the SHOOTER's ear.  You can shoot supersonic .22lr and get into the 120db range, or in the case of this Tavor 150gr .300blk and be in the 135db range at the ear.  However...

2.) Yes obviously you should still always using hearing protection, and no one is advocating otherwise (including Tim in the video).  OSHA and others give 140db as the level of INSTANT PERMANENT HEARING LOSS AT ANY LEVEL OF EXPOSURE.  In other words, if something is louder than 140db, you are going to lose part of your hearing very likely, even if exposure is very low.  However, OSHA and others give anything 85db< as causing hearing loss if exposed for 35+ hours a week.  Hearing loss is cumulative, and the log scale db works on, the higher you go, the less you need to cause damage.  So yeah, even a 135db suppressed round is still a terrible thing to shoot without earpro, or even double earpro.  BUT it does mean that if you are hunting or defending your home at 4am without earpro, then you don't necessarily instantly cause yourself hearing loss and/or loss of situational awareness.

In sum: The Tavor+Q Suppressor in the video is "OSHA hearing safe" in that you won't instantly lose a part of your hearing, and nothing more.  It is still way above the level recommended to use hearing protection.

Now back on topic, does anyone have video of .300blk ARs with suppressed supers being tested at the ear?  Would be an interesting comparison.
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Leonitus
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« Reply #11 on: October 24, 2017, 01:31:10 PM »

Edited die to reading comprehension failure.

I need more coffee..... Tongue
« Last Edit: October 24, 2017, 02:33:06 PM by Leonitus » Logged
Potss
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« Reply #12 on: October 24, 2017, 01:43:46 PM »

You clearly didn't read my comment.  Please, read first, then post.
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Leonitus
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« Reply #13 on: October 24, 2017, 02:33:23 PM »

Done....
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Hit Factor
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« Reply #14 on: October 24, 2017, 02:54:49 PM »



Tinnitus really sucks..  Don't play stupid games.

Tinnitus is the one thing I can always hear.

Sucks for sure.
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Leonitus
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« Reply #15 on: October 24, 2017, 03:40:45 PM »



Tinnitus really sucks..  Don't play stupid games.

Tinnitus is the one thing I can always hear.

Sucks for sure.

+1
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RabbitSlayer
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« Reply #16 on: October 25, 2017, 05:22:10 PM »

Ok some very misleading and incorrect comments in here.

1.) Yes all supersonic rounds will have a crack at about 150db or so.  However this occurs far enough away from the shooter that it DOESN'T EFFECT THE SHOOTER. 
(Snip)
In sum: The Tavor+Q Suppressor in the video is "OSHA hearing safe" in that you won't instantly lose a part of your hearing, and nothing more.  It is still way above the level recommended to use hearing protection.

You claim that a bullet breaking the sound barrier in open air 2-3 feet away from your face is far enough to not be a concern?
Wrong
Supersonic suppressed will never be hearing safe as the bullet in flight still breaks the SPL threshold for permanent damage for impulse noise.  This is well documented.

How about you site some scientific sources to back up your claims, because I am saying you are wrong and I will use sources and personal experience to back my argument.
Chieghton University and OSHA Disagree with your statements per their published literature on the matter.  Not to mention that most doctors disagree with OSHA, and say that much lower db levels will cause permanent damage than what OSHA says.. But for sake of argument lets focus on OSHA and the like..

You claim OSHA would say this is hearing safe ?  Wrong, here is just a snipbit of what OSHA and Crieghton University have to say about that.

Quote
How much noise is too much?
85 Decibels (dB) - the "Action Level" where hearing protection is required.
90 dB - the OSHA, 8 hour average exposure limit.
100 dB - exposures longer than 15 minutes are not recommended.
110 dB - regular exposure of more than 1 minute risks permanent hearing loss

Quote
Properly fitted earplugs or muffs reduce noise 15 to 30 dB. The better earplugs and
muffs are approximately equal in sound reduction, although earplugs are better for low
frequency noise and earmuffs for high frequency noise. Simultaneous use of earplugs
and muffs usually adds 10 to 15 dB more protection than either used alone. Combined
use should be considered when noise exceeds 105 dB.

https://www.creighton.edu/fileadmin/user/AdminFinance/Facilities/EHS/docs/Training/Hearing_protection.pdf




Quote
Potential Hazards:   

Some operations in the shipyard produce excessive noise, which may lead to hearing loss. Some of the loudest ship repair operations include:
Abrasive blasting (105-112 dBA)
Needle gunning (113 dBA)
Scaling
Grinding (108-110 dBA)
Carbon Arcing/Arc gouging (102-118 dBA)
Pneumatic pumps (100 dBA)
High-pressure steam cleaning

There is also a compounding effect per OSHA stating that combined noise levels also need to be taken into the equation as well.

Quote
Duration per day, hours   | Sound level dBA slow response
____________________________|_________________________________
                            |
8...........................|                    90
6...........................|                    92
4...........................|                    95
3...........................|                    97
2...........................|                   100
1 1/2 ......................|                   102
1...........................|                   105
1/2 ........................|                   110
1/4  or less................|                   115
____________________________|________________________________
Footnote(1) When the daily noise exposure is composed of two or
more periods of noise exposure of different levels, their combined
effect should be considered
, rather than the individual effect of
each. If the sum of the following fractions: C(1)/T(1) + C(2)/T(2)
C(n)/T(n) exceeds unity, then, the mixed exposure should be
considered to exceed the limit value. Cn indicates the total time of
exposure at a specified noise level, and Tn indicates the total time
of exposure permitted at that level. Exposure to impulsive or impact
noise should not exceed 140 dB peak sound pressure level.


I will post more quotes from the scientific community if needed, but arguing about this is very immature.  It is generally well known that loud noises are bad for your hearing, and that hearing loss is permanent.

 I have shot plenty with suppressed supersonic and calibers to understand this.  Everytime I shot a supersonic bullet with a suppressor from any gun without ear pro, it made my ears ring from the first shot. 

You can do whatever you want with your own ears, if you want to play tough guy and get hearing damage that is your own choice to make.  Every suppressor forum will tell you that supersonic bullets with a suppressor are not technically hearing safe.  So I am not going to sit around and play along with these false statements Tim made which could encourage people to self inflict permanent hearing damage.

Of course it is better to use a suppressor with out ear plugs than fire a gun without a suppressor without ear plugs... But it is still not considered hearings safe by the scientific community.  It will save your ears in a active shooter situation, but sitting around plinking with a suppressor and supersonic ammo will cause hearing damage.

MAC/Tim implied the Tavor is hearing safe with supersonic ammo and a fancy suppressor; he was wrong, he made a false statement END OF STORY.

Don't take my word for it, read the hundreds of other threads about this subject on the internet.  I'm done arguing that water is wet or that the sky is blue to people who are convinced that water is dry and the sky is red.

https://www.ar15.com/forums/armory/Is_there_really_a_hearing_safe_5_56_Suppressor_/20-430847/


http://www.m4carbine.net/archive/index.php/t-93033.html





« Last Edit: October 25, 2017, 06:01:38 PM by RabbitSlayer » Logged

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Leonitus
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« Reply #17 on: October 25, 2017, 10:08:22 PM »

Tinnitus sucks......do ALL you can to avoid it.

Once you get it, there is no going back.

Donít be a dumbass
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Rastoff
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« Reply #18 on: October 26, 2017, 12:49:11 AM »

The crack is the sound barrier being broken, which is not "hearing safe"  see my last comment.
It is well known hypersonic velocity is not hearing safe, research it on suppressor forums.
I work at Edwards AFB. I hear sonic booms regularly. I know what what it means and what happens when the sound barrier is broken.

Hypersonic is generally considered Mach 5 or greater. No one has a gun that fires a bullet at 5,625fps or more.

Now, in order for a bullet breaking the sound barrier to damage hearing, the listener would have to be in the shock wave as it breaks the sound barrier. That is where the sound is loudest. Everywhere else, the SPL will be quite less.

Further, the magnitude of the sound is directly proportional to the size of the object creating the wave. Therefore, a plane is loud and a bullet, not so much.

Further still, if every sonic boom is "not hearing safe", as you say, why don't people get hearing damage from a whip?

Then, I find it singularly amazing that you're trying to tell us this when I just told you that I've stood behind someone firing a .308Win traveling 2,650fps (twice the speed of sound) and it was far under the damage level. Are you calling me a liar?
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kingof9x
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« Reply #19 on: November 14, 2017, 08:21:27 PM »

some anecdotal "evidence" for this conversation. Here is a select fire suppressed x95 in .300 blackout. I don't remember what brand ammo we were using, but it was subsonic. The gun belongs to IWI.

https://www.instagram.com/p/BbIW9pAHsj4/
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