SBR’s and SBS’ too loud?

[Jessesky]

It’s easy to forget how loud guns are when we train with ear pro.

One thing that often gets overlooked in gun reviews is noise. In the gun training/author world you will find SBR’s and SBS’ are touted for the title of perfect home defense and PDW weapon. All I think of when I see them is “ouch! My ears”

I feel that noise gets overlooked because it is somewhat intangible compared to the other stats which are more definitive such as capacity, energy, OAL etc.

I have not had the honor of firing an SBR or SBS indoors (which is what they are intended for) though I imagine it to be deafening, blinding, and disorienting.

Thankfully, I have not been in any sort of situation where I’ve needed to discharge a weapon so I don’t know the effects of adrenaline. Although I can’t imagine adrenaline makes up for the drastic concussion and flash. What do you think?Do the pros outweigh the major cons I’m seeing?

I was contemplating going to an SBS. Now After seeing the blast and flash from federal flight control in an 18”, I think I may stick with my less maneuverable 20” mossberg 590.

 

[MachIVshooter]

I feel that noise gets overlooked because it is somewhat intangible compared to the other stats which are more definitive such as capacity, energy, OAL etc.

SPL is not intangible at all. There's a very well established and oft cited logarithmic unit for measuring it; the decibel.

The difference in SPL between an 18" and your 20" shotgun is nil. Both will produce dBA readings in the 160 range, causing instant, permanent hearing loss.

You have two options to protect your ears. One is worn by you, the other by your firearm. My HD weapons are configured so I needn't worry about the kind I have to put on my ears.

 

[Telekinesis]

Yep, there is a lot of work on understanding sound levels (mostly in the suppressor world) but MachIVshooter is right, there's not much difference between a 16" barreled AR and a SBR. Maybe if you're looking at a 7" barreled .223.... but both are going to remove a whole bunch of hearing if you shoot them indoors without a can or ear pro.

Adrenaline will not protect you from hearing damage if you fire without ear protection. At most it might make you not notice the sound as much, bit it will still be damaging your hearing.

The reason magazines and gun reviews don't talk about sound level is because doing accurate sound level testing is a pretty involved process which requires expensive sound meters (an iPhone dB meter doesn't cut it - you're looking at a couple grand per meter, and you usually want 2-3) and good software. And to add to that, it's just not that fun to stand there and record that kinda data unless you're getting numbers off of your suppressors. Then there could be arguments about properly calibrating the meter and at that point you either believe in their process or you throw out all their data. All to find that "yes, this will still hurt your hearing if fired without ear pro..."

 

[Deus Machina]

This is one reason I've never felt the need to pay for an SBR or SBS tax.
If you have the money, it might be better to use a 10" SBR with 6" of can on it instead of a plain 16" barrel.
If not, I think the best use for an SBR is in a pistol-caliber carbine, especially if you're partial to slow-and-heavy. The extra length may help burn off some powder that would otherwise be blast, and depending on the gun might at least get it a couple inches further way from your ears.
Either way, I'd prefer to never find out. My ears are bad enough already.

 

[6.8KT]

Yeah, not being able to hear -- because your ears are ringing -- in a situation where someone is still in or around your house... That would suck.

 

[DoubleMag]

You have two options to protect your ears. One is worn by you, the other by your firearm.

Option #3, do both

 

[FL-NC]

I have had the "opportunity" to fire (or be near to them being fired) handguns, shotguns, carbines, machine guns, and rifles of all types (not to mention things that actually explode) indoors and outdoors without hearing protection- never by choice- and it SUCKS. Rifles suck the worst, and it seems the shorter ones hold a special sucky place- maybe because it is happening a little closer to your face, or maybe due to the muzzle devices often screwed onto the ends of these things. I imagine everyone here has probably at least either forgot to use their ear-pro at the range, or doesn't wear it in the deer stand, or at least been in the vicinity of an accident. How was that? Overseas off-duty I kept foam ear plugs safety pinned in my hat for theoretical use in the event something happened (toss-up if I would have the time or remember to put them in) and I kept a set of electronic muffs in a pouch on my body armor. And I'm not going to store an expensive suppressor "ready for use" (or theft) in my house. Also, I'm not sleeping with muffs on my head or plugs in my ears. In my estimation, if you get into an "unplanned" gunfight, plan on some ear damage. Maybe some of the LE types here can comment on their experiences.

 

[jmorris]

My 10.5” SBR isn’t as obnoxious as my 18” 3 gun rifle with a brake on it. Put a can on it and it’s much better and about the same length as a 16”, just a lot quieter.

 

[AlexanderA]

In my estimation, if you get into an "unplanned" gunfight, plan on some ear damage.

The choice there would be simple: your hearing or your life. A self-defense shooting is a bad thing to happen, no matter how you look at it.

 

[Jessesky]

SPL is not intangible at all. There's a very well established and oft cited logarithmic unit for measuring it; the decibel.

The difference in SPL between an 18" and your 20" shotgun is nil. Both will u dBA readings in the 160 range, causing instant, permanent hearing loss.okjjtkk

You have two options to protect your ears. One is worn by you, the otuher by your firearm. My HD weapons are configured so I needn't worry about the kind I have to put on my ears.View attachment 822244

SPL is not intangible at all. There's a very well established and oft cited logarithmic unit for measuring it; the decibel.

The difference in SPL between an 18" and your 20" shotgun is nil. Both will produce dBA readings in the 160 range, causing instant, permanent hearing loss.

You have two options to protect your ears. One is worn by you, the other by your firearm. My HD weapons are configured so I needn't worry about the kind I have to put on my ears.View attachment 822244

By intangible I meant how it effects the shooter. Of course we can measure the decibel, but there can be many different types of sound that are at the same decibel level. It is difficult to measure how it effects each individual shooter beyond just the level. There is barely a difference in decibel level between an SBR and a carbine, but we both know which one has more concussive force.

 

[Madcap_Magician]

I'm curious about the relative loudness of PCCs at 16" and SBR lengths versus pistols, myself.

 

[dodo bird]

All I know is I double up with plugs and muffs at the range. Only exception maybe 22 rifle with only muffs. Shooting dove with 12 gauge unprotected didn’t help me in my younger years. Not to mention rock concerts, firecrackers, and airplane noise.

 

[MachIVshooter]

I'm curious about the relative loudness of PCCs at 16" and SBR lengths versus pistols, myself.

While the muzzle numbers get lower as barrels get longer, PCCs are often worse at the shooter's ear due to blowback gun port noise. Locked breech pistols have less of it, and it's further from your head.

This is one of the biggest challenges in effectively suppressing autoloaders, especially blowback guns. My ultralight folding 9mm carbine meters 12 dB higher at shooter's ear than muzzle with my Phoenix IX can on it. My CZ83? It's almost as loud to the shooter suppressed as unsuppressed due to port noise.

By intangible I meant how it effects the shooter. Of course we can measure the decibel, but there can be many different types of sound that are at the same decibel level. It is difficult to measure how it effects each individual shooter beyond just the level. There is barely a difference in decibel level between an SBR and a carbine, but we both know which one has more concussive force.

Of course shorter barrels have higher exit pressure. That's why magnum revolvers are one of the worse offenders, so much exiting at the cylinder gap. But whether it's your 16" 5.56 carbine at 161 dB or a 10.5" at 164 dB, you're over the threshold of hearing safe SPL for impulse noises by >100 times. How that affects each shooter is that you won't be able to hear much of anything for awhile, and you'll have lost hearing sensitivity forever even once the ringing stops (if it stops). Yes, better to be alive and half deaf than pushing up daisies, but I choose alive and not deaf.

As for the utility of SBR, see:

better to use a 10" SBR with 6" of can on it instead of a plain 16" barrel.

A suppressed SBR (or "one stamp" short barrel with permanent suppressor) is still very handy, roughly the same length as a title 1 carbine and not much heavier if you choose an appropriate can. A 5"-6" quality suppressor will bring a 10" AR down to about 140 dBA at the ear and almost completely eliminate the flash and concussion.

Yes, I do have an agenda to get the entire shooting community on board with suppressors. Home defense is one of the applications in which they make the most sense, followed by hunting, both being circumstances where ear pro puts you at a disadvantage and you may not have time to get it on anyway.

 

[hso]

I have not had the honor of firing an SBR or SBS indoors (which is what they are intended for) though I imagine it to be deafening, blinding, and disorienting.

That's a lot of concern for someone without the experience of having shot them indoors. Matter of fact, it can be, but no more than a lot of pistols.

A suppressed SBR (or "one stamp" short barrel with permanent suppressor) is still very handy, roughly the same length as a title 1 carbine and not much heavier if you choose an appropriate can. A 5"-6" quality suppressor will bring a 10" AR down to about 140 dBA at the ear and almost completely eliminate the flash and concussion.

A suppressed SBR or SBS is where things begin to shine. Maneuverability along with the suppression to 140dB with the greater ballistic energy delivered to the target is a plus when inside.

 

[Old Dog]

I have not had the honor of firing an SBR or SBS indoors (which is what they are intended for) though I imagine it to be deafening, blinding, and disorienting.

Unless an SBR is suppressed, the blast is heinous ... and if you're next to the shooter, you'll feel the blast, pressure and concussion ... Even next to one at an outdoor range sucks. I'd just rather not.

 

[Madcap_Magician]

While the muzzle numbers get lower as barrels get longer, PCCs are often worse at the shooter's ear due to blowback gun port noise. Locked breech pistols have less of it, and it's further from your head.

This is one of the biggest challenges in effectively suppressing autoloaders, especially blowback guns. My ultralight folding 9mm carbine meters 12 dB higher at shooter's ear than muzzle with my Phoenix IX can on it. My CZ83? It's almost as loud to the shooter suppressed as unsuppressed due to port noise.

I am mostly interested in doing a 4.5" or 6" Sig MPX with a suppressor to bring it to roughly the same size as the 8" gun. I have heard the gas-to-face is higher, but since it's gas-operated instead of blowback-operated, I wonder...

 

[6.8KT]

I think a suppressed PCC shooting heavy-for-caliber bullets would be a good home defense weapon for most scenarios.

 

[MachIVshooter]

I am mostly interested in doing a 4.5" or 6" Sig MPX with a suppressor to bring it to roughly the same size as the 8" gun. I have heard the gas-to-face is higher, but since it's gas-operated instead of blowback-operated, I wonder...

The gas in the face problem is generally overstated. My CMR30 SBR is really the only semi auto I have found it to be truly offensive.

Though I have no personal experience with one, I think the MPX is probably one of the most ideal PCC/SMG hosts with it's gas operation.

I think a suppressed PCC shooting heavy-for-caliber bullets would be a good home defense weapon for most scenarios.

Assuming that it's one without atrocious port noise, yes. But almost any blowback will snap your ears. Even my Suomi M31 post sample with a 2-1/2 pound bolt produced higher at-ear dBs than the 10.5" AR with my 5" Five-By Five can posted above (141.31 vs. 140.03). That was metered inside a 12x24 wood structure on a B&K Pulse system, same morning. And this was with my Vorticis 45, a can specifically designed to reduce backpressure with a large coaxial chamber and careful application of helixes within.

For a centerfire semi-auto firearm to be decently quiet at shooter's ear suppressed, it needs to have some kind of delayed blowback or locked breech operating system.

 

[6.8KT]

Assuming that it's one without atrocious port noise, yes. But almost any blowback will snap your ears. Even my Suomi M31 post sample with a 2-1/2 pound bolt produced higher at-ear dBs than the 10.5" AR with my 5" Five-By Five can posted above (141.31 vs. 140.03). That was metered inside a 12x24 wood structure on a B&K Pulse system, same morning. And this was with my Vorticis 45, a can specifically designed to reduce backpressure with a large coaxial chamber and careful application of helixes within.

For a centerfire semi-auto firearm to be decently quiet at shooter's ear suppressed, it needs to have some kind of delayed blowback or locked breech operating system.

What you say makes sense, but this blowback-operated Sub2000 seems awfully quiet with suppressor.

 

[MachIVshooter]

What you say makes sense, but this blowback-operated Sub2000 seems awfully quiet with suppressor.

Videos are deceiving. Noise leveling microphones & software in recording and in playback; it won't capture or portray the peak impulse. This is a video of my Suomi with the Vorticis:

 

[6.8KT]

Videos are deceiving. Noise leveling microphones & software in recording and in playback; it won't capture or portray the peak impulse. This is a video of my Suomi with the Vorticis:

Nice rig.
So were your ears ringing at all after that string of fire; or if they weren't, would they've had you been inside?

I have to think that, for the price, the sound suppression would be "good enough" for something like a Sub2000 + can.
I guess a suppressed AR would cost about the same.
But which would be quieter at the shooter's ear? Surely the AR would be louder at distance with its supersonic bullet.

 

[mjsdwash]

What you say makes sense, but this blowback-operated Sub2000 seems awfully quiet with suppressor.

What MachIV said, plus he's also thirty feet away, in a wide open area, which may not seem alike a lot, but 30' its pretty far in reference to that crack at the bolt. On top of that, the ejections side is usually louder too.

 

[MachIVshooter]

Nice rig.
So were your ears ringing at all after that string of fire; or if they weren't, would they've had you been inside?

No. Shooting outdoors lowers dB slightly, and reflected noise that hits our ears considerably. Also, the Pulse picks up higher peak impulses than the B&K 2209 or Larson-Davis meters used by most of the industry to test; a 2209 outdoors would put the at-ear levels mid 130s.

I don't know if the actual OSHA hearing safe level will be adjusted upward with more accurate/sensitive meters like the Pulse that show previously-"known" sub-140 dBA noises to be >140, but I can tell you that almost everything meters 5-10 dB higher on the pulse than published numbers. SilencerCo Osprey .45 is listed at 131 dBA, but Pulse averaged 137.48.

But which would be quieter at the shooter's ear? Surely the AR would be louder at distance with its supersonic bullet.

The supersonic crack isn't really present right at the muzzle; if you put bullets into the ground just a few feet away, you won't hear it:

Starting after :30



With the way acoustic attenuation works, dropping approximately 6 dB for every doubling of distance from the source, a sonic crack happening 12-15 feet forward of the shooter is not a dangerous impulse noise.

This phenomenon is also important to note when evaluating published figures for suppression or NRR; if a manufacturer puts the mic at 5 meters instead of the mil spec 1 meter *cough*OSS*cough*, you're gonna see really impressive suppression figures that are utterly meaningless if you fire your gun with your hands, not with a string from 15 feet away.

Properly tuned ARs with good cans can be sub-140 at ear, but high back pressure cans or systems which haven't had gas adjustment and/or buffer weight adjustment will often be mid-140s. Most other gas operated semi-autos will be mid to high 140s at ear due to piston pop (AK, FAL, etc), and there's really not a lot you can do about it. The AR is a superior suppressor host due to a lower volume of cooler gas being vented later in the cycle.

 

[roo_ster]

I have shot plenty indoors, some of it paid for the taxpayer. Most with earpro, some without. Muzzle blast indoors, both noise and pressure, sucks rocks and can be unpleasant even with doubled-up earpro.

That said, some things produce more muzzle blast than others:
Higher pressure load
Shorter bbl
Revolver vs recoil-operated semi-auto
Blowback vs recoil-operated semi-auto
Muzzle brakes

At present, I have at the ready a couple 12ga shotguns with 18" and 20" barrels and my HD long guns. My HD pistols consist of a .357mag revolver loaded with .38spl FBI loads and a 1911 in .45ACP.

I will hold off on the SBS, SBR, and suppressors until the NFA foolishness is rectified. After that, I would consider a SBR with a long-ish suppressor.

 

[ATLDave]

On the topic of PCC's, I'd throw this in. PCC's (mostly blowback ARis-9mm things) have gotten very popular in the last 2 years in USPSA. That's a sport where a shot timer is used. (A shot timer is a device that records elapsed time between a start signal and the last gunshot-loud noise it detects, which means it relies upon the loudness of the gun to trigger the timing.)

There are some PCC's that are about as loud as 9mm locked-breach handguns, and some that are (without a suppressor) so quiet they pose challenges for the range officer running the timer. That is not to say they are hearing-safe without ear protection (ear pro is mandatory in the sport), but there are some that are definitely less abusive than even service pistols. This may depend heavily both on the load being shot (small charges of fast powder are common, and people generally aren't trying to push their projectiles very hard) and on the specific buffer/bolt setup.

But I would disagree, based on my experience having to play tight "man coverage" as an RO to keep the timer working on some of these guys, that blowback 9mm PCC's are inherently louder.