Dead Air Arm Suppressor for SBR?

[Pugsbrew]

OK, this will be my first venture in to suppressors. I'm looking at the DAA Sandman Ti. Any comments on their products? Any others I should consider?

Thanks

ps The suppressor will most likely stay on the SBR, so no need for QD.

[LRRPF52]

They're nice. Rated to .300 Win Mag, but I would want to see a minimum barrel length rating.

Probably won't be an issue with 6.5 Grendel and the weight they're showing for it.

[am4966]

Dead Air don’t have any min length for there cans. They are tough as nails

[fixin]

Silencer co. carries some good looking stuff, make sure whatever can you go with to hunt down decibel data on it outside of manufacturer spec. There is no single set standard on decibel testing, more a conglomerate of ways to test. Recently the military picked up a 6 inches from the right ear test that I personally like. That for me is best case scenario for testing a can since it is next to the shooter's ear as opposed to anywhere else. My first thread on here was asking for decibel data for the Q LLC. Trashpanda and nobody had any data on it, so by the looks I'll be guinea pigging it once my form 4 shoots back to me.

[Klem]

Silencer co. carries some good looking stuff, make sure whatever can you go with to hunt down decibel data on it outside of manufacturer spec. There is no single set standard on decibel testing, more a conglomerate of ways to test. Recently the military picked up a 6 inches from the right ear test that I personally like. That for me is best case scenario for testing a can since it is next to the shooter's ear as opposed to anywhere else. My first thread on here was asking for decibel data for the Q LLC. Trashpanda and nobody had any data on it, so by the looks I'll be guinea pigging it once my form 4 shoots back to me.

fixin,

There has been a handful of suppressor studies over the years including the World Health Organisation that has informed the US military's current standard for severe noise exposure Damage Risk Criteria (DRC). The current standard is MIL-STD 1474-E which was promulgated in 2015. Prior to that has been 1474-D since 1997. The previous 1997 standard assumed that all sound above 140db (peak impulse) would be mitigated by people using hearing protection. This is why manufacturers have labelled some of their suppressors as 'hearing safe' if the sound is below 140 at wherever they place the microphone near the gun. As you might imagine peak db levels vary widely depending on where the mike is around the gun, but also the type of action. For example, Lobarinas and his colleagues in 2016 conducted a study to find out what db reduction you would have with a suppressed semi auto AR15 using 223 and 300BLK. They found the db reduction varied depending on what ear you were recording. The left ear recorded on average (it varied because they tested more than one suppressor) a 20-30db reduction while the right ear which was more exposed to the ejection port was less at about 10-18db.

Getting back to the formal studies and standards finding a clear quantifiable link between sound pressure and what hearing damage results is imprecise. We end up with models which get massaged in subsequent studies. The current MIL-STD1474 uses an electroacoustic model designed by Price and Kalb (1991) called the Auditory Hazard Assessment Algorithm for Humans (AHAAH). The model attempts to predict the total energy received by the cochlea which causes temporary and permanent damage. Predicting hearing damage is further confounded by how we test for sound around a firearm. I've already mentioned how sound varies greatly depending on where you put the mike but also what you are measuring. Audiologists are prone to measuring with an array of microphones, averaging the pressure and then attempting to remove any reflections from things like floors, walls and in shooting scenario's, tables and benches. Manufacturers however tend to source a quality mike and test for pinpoint sound at points, for example, 2metres a right angles to the muzzle. Some academics do the same, so there is a lack of convention across the world in this area. I hope by all this I have created a sense that it depends on standards and definitions. What is for certain, and I keep stressing this on the forum is that no suppressor is hearing safe. I know in the US you guys go to a lot of expense and effort to get these things and they do mitigate sound but please don't be tempted into thinking you can use them without also using ear protection. If you think that kind of defeats the purpose and effort of getting one then good luck in your old age when that bus you didn't hear ends up bowling you over, or the telephone that never rings (high frequencies suffer the most).

A good read that concludes external ear protection should be worn when using suppressors has just been published in the Journal of Audiology by Murphy et al (2018). These guys are from the Hearing Loss prevention team at the National Institute for Occ health and Safety in Cinncinati. They focus on the two main sounds generated by a firearm; the sonic-boom and the muzzle blast. The sonic boom is called the N-Curve due to the nature of its pressure over time. It looks like the letter 'N' on a graph. The point being is that suppressors can do nothing to mitigate the sonic crack. Peak sound pressure recorded by Rasmussen's 2009 study had the sonic boom N-Wave at 172db while the muzzle blast was 175db. If you are firing subsonic ammo that of course eliminates the N-Curve and you are left with the muzzle blast.
[ATTACH=CONFIG]12042[/ATTACH]

Murphy's team placed 10 microphones around the shooter and recorded the noise reduction using Gemtec HVT-QM (.308), a G5 (.223) and Outback IID (.22) suppressors on two bolt guns; a Savage, a Rem 700, and a Ruger Charger .22 handgun.
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Here is their paper's conclusion;

[INDENT]Conclusions
The measurements described in this paper are in general agreement with those reported previously. The suppressors reduced exposures at the ear between 17 and 26 dB peak sound pressure level and reduced the 8 h equivalent A-weighted energy between 9 and 21 dB depending upon the firearm and ammunition. Noise reductions Figure 8. Sound power as a function of the one-third octave bands after the N-wave was extracted. The N-wave contributed substantially to the energy measured at the microphones in the front half of the hemisphere in Study 2. Firearm suppressors and auditory risk reduction S39 observed for the instructor’s position about a metre behind the shooter were between 20 and 28 dB peak sound pressure level and between 11 and 26 dB LAeq,8h. Although these results imply a substantial risk reduction, the limited numbers of firearms, suppressors and environmental conditions evaluated in this study are insufficient to consider any combination of gun and suppressor ‘hearing safe'. Thus, hearing protection should be worn whenever firing a gun. For more energetic firearms when target shooting double protection is warranted for the unsuppressed gun and single protection is needed for a suppressed gun.[/INDENT]

These guys make the point that they conducted the test in the open and above the ground. If you shoot in a blind, or under a roof, or inside CQB the surface reflections increase the hazard.

My overall point is there are a bunch of suppressor studies going on all the time in controlled environments that inform institutions and standards. While there is little consensus of how firearm sound should be measured there is consensus that high-power centrefire suppressed firearms are not hearing safe. They do however reduce the damage and help those around you, and won't scare game as much. Plus setting aside any tactical reasons to use them they are simply good fun to shoot. Ironically, if you don't use ear protection with a suppressor you will end up more deaf than if you didn't have the suppressor and wore the usual ear protection.


References.

Lobarinas, E., Scott, R., Spankovich, C. and Le Prell, C. G. (2016). Differential Effects of Suppressors on Hazardous Sound Pressure Levels Generated by AR-15 Rifles: Considerations for Recreational Shooters, Law Enforcement, and the Military. International Journal of Audiology 55 (1): S59–S71.

Murphy, W. J., Flamme, G. A., Campbell, A. R., Zechmann, E. L., Tasko, S. M., Lankford, J. E., Meinke, D. K., Finan, D. S. & Stewart, M. (2018). The reduction of gunshot noise and auditory risk through the use of firearm suppressors and low-velocity ammunition, International Journal of Audiology, 57up1, S28-S41, DOI: 10.1080/14992027.2017.1407459
Link: https://doi.org/10.1080/14992027.2017.1407459

Price, G. R. and Kalb, J. (1991). Insights into Hazard from Intense Impulses from a Mathematical-model of the Ear. Journal of the Acoustical Society of America 90 (1): 219–227.

Rasmussen, P., Flamme, G. A., Stewart, M., Meinke, D. K. and Lankford. J. E. (2009). Measuring Recreational Firearm Noise. Sound & Vibration 43 (8): 14–18.

[Sticks]

15 years and counting of Pneumatic tools and diesel engines, 28 years motorcycle riding sans brain bucket, never mind stupid youth days shooting sans ear plugs...One can't break what is already broken.

[fixin]

That's all great info, however the gentleman who originally posted the thread is simply asking what suppressor to go with, to which my reply was/is to do research and question manufacturer spec. As with all things sometimes manufacturers don't tell the whole story, so it is good to get a 2nd opinion. On top of that your info highlighted the fact that there isn't a singular type of testing as I noted, MY preference is with the 6in off of the ear test, however that is MINE ALONE. At no point did I say "don't wear hearing pro" I am giving a personal opinion while at the same time telling Mr.Pugsbrew to scour whatever objective, researched based info he may be able to find in order to make a logical and practical decision. Although your info is awesome, why didn't you message me this information instead? Help this gentleman out, he is looking at getting a deadair sandman TI, however he is open to other suggestions.

[Klem]

That's all great info, however the gentleman who originally posted the thread is simply asking what suppressor to go with, to which my reply was/is to do research and question manufacturer spec. As with all things sometimes manufacturers don't tell the whole story, so it is good to get a 2nd opinion. On top of that your info highlighted the fact that there isn't a singular type of testing as I noted, MY preference is with the 6in off of the ear test, however that is MINE ALONE. At no point did I say "don't wear hearing pro" I am giving a personal opinion while at the same time telling Mr.Pugsbrew to scour whatever objective, researched based info he may be able to find in order to make a logical and practical decision. Although your info is awesome, why didn't you message me this information instead? Help this gentleman out, he is looking at getting a deadair sandman TI, however he is open to other suggestions.

fixin,

I thought I was taking the effort to expand on what you were saying. I agree with you in parts and expand on what you are saying in other parts, along with some advice on using suppressors. I know something about this topic because it is partly what I do for a living. I was not having a go at you so please lighten-up as I make the effort to share what I know with everyone, including the OP.

As for advising the OP on what brand of suppressor to purchase I simply don't know. For that you'd want to have compared most suppressors in the same conditions and I don't think there would be many, if any who have done that. What I will say in general terms is I am a fan of modular, reflex (over-barrel) and light-weight designs. Modular means the suppressor unscrews into segments with each segment being one baffle. The baffles are not separate parts in an external tube, they are the external tube. In this way you are not limited by a solid cylinder but can choose the number of baffles for the suppression you want at the time. For example you might want to add more than usual if shooting Blackout subsonic given there's less force at the muzzle to turn the pressure 180 degrees into the expansion chamber. Plus with subsonic, without the sonic boom you have a real chance of making the thing 'quiet' and are prepared to tolerate a longer/heavier suppressor to achieve this. The length of the suppressor is only limited by cumulative run-out and flex, so you can have a can with either two baffles or 10. It is also a good design because you can glue the first segment to the threaded crown and unscrew the segments for cleaning and corrosion control. Take the segments off and you expose the crown and can push patches through. That's not to say you can't do that currently with proprietary notched muzzle devices but it is lighter and simpler. Otherwise you have to keep checking it is screwed on tight as it heats up, expands and comes loose...which probably happens more often than people admit.

The Odessa 9 by Dear Air is an example of a modular suppressor, https://deadairsilencers.com/products/odessa-9/

As for reflex designs, I like how the suppressor comes back down the barrel meaning the centre of gravity is closer to the shooter. With a muzzle-forward design the OAL of the rifle is longer to achieve the same noise reduction. Extending the AR hand-guard further than you hold it or prefer the bipod to be is not necessary so you may as well keep your hand-guard only to the length you need and use that exposed barrel for an expansion chamber. Typically expansion chambers need about 4" of exposed barrel back from the thread relief at the muzzle.

As for light-weight that speaks for itself, unless you intend doing all your shooting from a place near where you park your car. Either titanium or a combination of steel and alloy. Steel for hard wearing near the muzzle and alloy for when the pressure has dropped. All alloy suppressors don't last as with high-power centre-fires these things get absolutely hammered.

One last thought...I am convinced that sound comes through the walls of our suppressors. How much comes out the exit hole and how much radiates through the walls and how much back out the ejection port I don't know. I use covers and am convinced they go some way to make it quieter. If you are not planning on volume fire where the can heats up and starts smoking then a tight fitting neoprene cover or a heat resistant sleeve helps noise reduction (e.g. TAB Gear, https://www.milehighshooting.com/tab-gea...sor-cover/).

[grayfox]

OP, all good points above. I'm looking at my first one also but haven't looked at the Dead air ones. I'm leaning towards the TBAC ultra-7cb, it comes with a MB but there is also the direct thread version. It has a very good bunch of recommendations, is very light (9 oz) and uses Titanium to get there. The Accurate shooter blog survey found (the 2015 or 2016 I think) that 1/3 of the top 50 shooters in their PRS competition use the ultra7 or maybe 9, but the TBAC's, 3 yrs in a row.
http://precisionrifleblog.com/2015/02/20...uppressor/
So that may speak something additional towards how accurate it can be.

Another feature esp for direct thread is repeatable consistency as to POI shift, taking it off and then putting back on. Since the ultra CB is a TOMB (thread over muzzle brake) it threads on but the mating surface MB-Supp is a conical shape so much better seal and alignment, and more consistent in whatever POI shift it makes. For those times you do take it off and then re-install you will know what the shift is and can just dial for it.

The Dead Air could be a good choice too, just do your research and comparisons.

[Klem]

...

The Dead Air could be a good choice too, just do your research and comparisons.

I posted the Dead Air Odyssey-9 as an example of a modular design only. I have never used it and am not endorsing it. It is a 1.1" diameter 9mm handgun suppressor so unsuitable for the Grendel anyway. You can find examples of high-power, centre-fire modular suppressors if you look around.

The one time I attended the Sporting Rifle Match at the Whittington Centre all three of the TBAC luminaries were there (Zac, Ray 'Dog' and some quiet tall dude). The top shot prize was a TBAC suppressor. They also competed with everyone else which is great so I am just making the point that the long range tactical precision crowd might have a degree of TBAC loyalty because they have made the effort to get involved and embed themselves into the community. And good on them for doing this. Other manufacturers will be just as good however but finding which one is the best is the holy grail of difficult choices. The early model TBAC I handled on the day was heavy but since then they have come out with lighter offerings.

Regardless of which design you choose it needs to come off every time you store it. These things get heavily coated in carbon which in turn accumulates moisture. Leaving it attached to the end of your barrel in the worst possible place for corrosion control is asking for trouble.

[grayfox]

Regardless of which design you choose it needs to come off every time you store it. These things get heavily coated in carbon which in turn accumulates moisture. Leaving it attached to the end of your barrel in the worst possible place for corrosion control is asking for trouble.

Klem good point I did not know that!

[imaguy3]

Another feature esp for direct thread is repeatable consistency as to POI shift, taking it off and then putting back on. Since the ultra CB is a TOMB (thread over muzzle brake) it threads on but the mating surface MB-Supp is a conical shape so much better seal and alignment, and more consistent in whatever POI shift it makes. For those times you do take it off and then re-install you will know what the shift is and can just dial for it.

The Dead Air could be a good choice too, just do your research and comparisons.

The Dead Air is dead nuts repeatable with the POI shift. Their QD system is stupid proof. The can can only go on with one orientation, so long as you tighten it all the way everytime, the POI come back everytime you dismount/remount the can. I tested it on my bolt gun and AR's numerous times. This pic. was the norm, not a one time thing. I shot 3 rounds (outlined in black the hole behind the yellow was a previous outing), took the can off and played with it on my grendel... then put it back on my bolt gun and shot 2 more rounds... I can't ask for much better..

[imaguy3]

Here's a good video on the dead air mounting system.... https://www.youtube.com/watch?v=-_kbB7e4Tgs

Honestly I chose this system for my can instead of direct thread (I was looking at some others before deciding on the K)... for all the reasons in the video. I also chose the K b/c I wanted small and light for my hunting guns.

[Pugsbrew]

OK, any comments on Larue suppressor?

https://www.larue.com/products/larue-tra...eviews-tab

[Kswhitetails]

Thumbs way way up on the LaRue. I’ll edit later for more information. I love mine, and in the future when I test another can and on a bolt gun.

[mdewitt71]

I own a few 9mm and 22 cans but, nothing for a rifle yet.....
I think I might get a can for my Grendel and maybe AKs, need to research some models.
I do hear a lot of great reviews about Dead Air Sandman model.

[Bearcatrp]

My stamp just came in for my sandman-s. Didn’t want to long and it’s hearing safe according to the chart. Will share between bolt and AR’s, 308 version. If it’s as good as I read about, may order the long version for better sound suppression. I looked at the Ti. Being a direct thread on to the barrel, I decided against it after reading numerous posts about issues getting them off. Good luck on your decision.

[Thegrass13]

I currently run the sandman K on my sbr hunting setup and love it. I also have the sandman s for when I'm out at the range or hunting in box stands. Where I hunt is very thick and I hike pretty far in so the shorter can and barrel help a lot. If you want more of a general use can, the sandman S you can't go wrong with. Good luck man.

[LongPoke]

OK, this will be my first venture in to suppressors. I'm looking at the DAA Sandman Ti. Any comments on their products? Any others I should consider?

Thanks

ps The suppressor will most likely stay on the SBR, so no need for QD.

DeadAir Sandman Ti is an excellent choice for your Grendel.

OK, any comments on Larue suppressor?

https://www.larue.com/products/larue-tra...eviews-tab

Also a good choice, IIIIIFFFF you are buying the Ultimate Upper at the same time and therefore get the TranQuilo for $399. I would not pay more than that for it. It's too damn heavy.