[HIPOWER]

Hi folks. Would anyone want to hazzard a guess, or offer some experiences or information, on what would be the "quietest" combination of caliber, ammo, handgun and bbl. length?

My guess would be subsonic 9mm out of a 4" or 5" bbl.

Any thoughts?

[Hkmp5sd]

.22LR CB Caps or Colibris out of a revolver.

[HIPOWER]

I guess I should have qualified the question a little: What I meant was the least loud gun/ammo combo among "duty" calibers (9mm, 45ACP, etc...)

[Ala Dan]

Greeting's All-

Any handgun caliber IS NOT suitable for human ear's;
without proper hearing protection, one most likely would
end up deaf fairly quickly!:uhoh: :( :rolleyes:

Best wishes,
Ala Dan, N.R.A. Life Member

[Mal H]

What Dan said.

None of the standard service rounds are quiet, period. And therefore there can't be a "quietest" one of them. I'm only guessing since I haven't seen a decibel test of downloaded rounds, but I would think a subsonic bullet out of the biggest muzzle in the group would have the lowest 3 figure decibel rating. It's going to be the escaping gasses that create most of the noise. The lower the gas pressure and the larger the hole for the gas to escape, the lower the sound pressure level. My vote would go to a downloaded .45 ACP out of the longest barrel available in a semi-auto (no revolvers need apply). Heck, the .45 usually starts out subsonic as it is.

[Mark IV Series 80]

What I meant was the least loud gun/ammo combo among "duty" calibers I would use the 148 grain, .38 Special Target Wadcutter out of a 6 or 8 inch barrel.

[Hkmp5sd]

The sound of the gases exiting the firearm and the action (if applicable) movement is going to overcome the noise of a bullet, so subsonic in this case doesn't really matter.

I have a few suppressed firearms and use hearing protection when firing them because the action and gases that exit through the chamber when it opens are still loud enough to cause hearing damage with prolonged exposure.

If you are concerned about blowing your eardrums out and temporary blindness from the muzzle flash due to using a handgun in a defensive incident, you can at least minimize the flash buy using low flash ammo such as CorBon.

[Doc]

here we go with physics again

the decibel (actually the bel) is a logirhythmic (sp?) scale so an increase in 10 units is 100 times increase in pressure (if memory serves).
So a "quiet" shot (non-supresses) like a 22 short, colibri etc from a normal handgun barrel is still VERY LOUD.
Even if you could decrease the sound pressure level (the decibel number) 10 (from say 140 to 130)
by shooting such a load
that's still way too much overpressure for the human hearing apparatus.

Now if you ever read "Guns & Weapons for Law Enforcment" they regularly test supressors. Sometimes with rounds such as the Colibri, despite this the sound levels are routinely above 100 db which cannot be sustained by the human ear for any length of time or repeated frequency.

Anyone have a graphic of that db scales showing the numbers next to the sounds, you know whisper, conversation, up to jet engine...

Now if the question is relative (ie which caliber won't shake my dentures when I shoot it WITH appropriate hearing protection. The question becomes that which HIPOWER poses:
I guess I should have qualified the question a little: What I meant was the least loud gun/ammo combo among "duty" calibers (9mm, 45ACP, etc...)

There clearly any "hunting" caliber or round will be "louder" than any puffer load designed for speed & accuracy in shooting competetion. 9mm would be "quiet" compared to 44Mag or 454 Casul; but, both would still be very loud (unsupressed) with db in the same range 130-140 (just guessing)

[El Tejon]

HI, lots of variables. It depends--ammo lot number, manufacturer, hand load, area weapon discharged, "magnum" vs. +P+ vs. whatever.

Sounds like a good excuse as any for experiments. "Honey, it's for science!":)

[blue86buick]

So a "quiet" shot (non-supresses) like a 22 short, colibri etc from a normal handgun barrel is still VERY LOUD.

Is this because it's a handgun barrel? I've shot CB Long's from a rifle barrel (R 597) and they seem to be as quiet as my CO2 pellet pistol...which just makes a "pop". Not saying it's so quiet that your next door neighbors won't know you're shooting (and if they do, it's quiet enough they shouldn't care)...but your neighbors two doors down won't. (IMO)

Disclaimer: I'm not advocating shooting within city limits. Just saying you COULD w/o creating a disturbance from the noise.

[Doc]

bluebuick:

I was only thinking of handguns.

But the rule still applies to long guns too.
The subjective lessening is partially due to the shot being fired farther from your ears, and being shot from a longer barrel. However, if you put a sound meter (ie decibel meter) 1 meter lateral to the end of the barrel (the standard for measuring sounds) I THINK the sound pressure will still be very high, akin to the decrease I mentioned above (less than 10 decibels lower).

Wherre are all of those lurking physicist who were active in the night sight degradation discussion?

Hal M???
BenEzra???

[farscott]

The decibel (one-tenth of a bel) is a unit of ratiometric measurement; in other words, it is a way of comparing a value to some reference. The basic formula is dB(ref)= 10*log (x/ref), where log is the base 10 logarithim, x is the magntiude, and ref is the reference value or unit. Thus, one see terms like dBm (referenced to 1mW of power), dBuv (referenced to 1uV), and dBuV/m (referenced to 1uV/m).

The interesting thing about the dB measurements is that 3dB is double the reference value, 6dB is four times the reference value, and 10dB is ten times the reference value. 30dB is 1,000 times the reference value since the decibel is a logarithmic unit. If there is a minus sign in front of the unit, it means that value is smaller than the reference. If something has a measurement of -13dB, it is about 20 times lower than the reference value. If the value is -23dB, the value is about 200 times lower than the reference.

I do not know too much about sound pressure levels, but I was told a rule of thumb. Basically, it takes 10 times more sound pressure (10dB more) for the apparent volume of a sound to double. I believe that there are several compensatory curves for measuring the sound pressure levels; the idea is to better correspond to the ear's response. I have heard of "A"-weighting and "B"-weighting, but I am not sure of the compensation used.

[Doc]

ah the sound of physics...
I KNEW there were lurkers!! with greater expertise....:evil:

[Mannlicher]

You would be hard pressed to tell which was the loudest or quiter of the 'duty' rounds. Now when a 4 inch .44 mag goes off, that is louder, but all of the major calibers are loud.

[HIPOWER]

I realize that all duty calibers are very loud and should only be shot with hearing protection when possible. But surely, given the differences between 9mm and 45ACP, they must have different decibel signatures.

Generally speaking, I have noticed (with muffs on) that a Glock 17 with subsonic ammo seems to be "quieter" (relatively speaking) than a Glock 21 45ACP with 230 gr. hardball.

I realize they're all loud. I guess I'm wondering what would probably be the least detrimental to the shooter's hearing if he should need to fire in self defense.

[Hkmp5sd]

Oddly enough, I have a Colt Junior Colt in .22 Short that is louder than some .380/9mm pistols I have.

[Doc]

in real terms, if you fire your weapon in self defense, even if you empty the magazine, you wont notice (adrenaline dump, etc)

just like when you are hunting

;)

you might have some ringing, might not
but ANY rifle caliber is gonna be louder, alot louder.

Mas Ayoob says that any center fire rifle inside a building for self defense, results in permanent hearing loss, dont know if thats true tho

[22luvr]

I'm really glad there are smart people out there who understand formulas and equations............Y'all just blew me away!

From a laymen's point of view........I simply don't buy the claims I've heard on some forums that LEO's and others can "block" out the damaging effects of gunfire without hearing protection. It is a very real physical thing, not something the mind can mentally block out at will.

What hurts your ear in shooting without any ear canal protection are the super compressed airwaves. If you've shot next to anyone touching off .357's, you can FEEL the compression as it buffets you.

The same phenomenon that Tim McVea used to bring down the Murrah building in Oklahoma City, (fuel-air-compressive-explosion) on a larger scale, is the same thing that damages your unprotected ears when firing a handgun.

I always wear hearing protection and sometimes double up with in-the-ear-canal plugs and muffs.

[curt]

actually i have heard of a physical process where the ear can protect itself somewhat from loud noises, don't remember the process and you won't catch me without muffs or plugs.

If you ever have to use a firearm in defense of your life or someone elses then your life is going to be altered in a big way a little loss of hearing won't be an issue. I would never compromise the already minimal performance of any handgun round by trying to minimize the sound. If your really worried about it though there are a variety of electronic hearing protection devices on the market that could be donned fairly quickly and there are legal means to obtain suppressors.

[gudel]

lots of physics people but no biology people, don't understand how hearing works (must've been that formulas). when there's loud noise, your hearing bones (maleus, incus and staphe) muscles will pull it out from the tympany so that you don't get hearing overload hence puncturing your ear drum. The tensor tympani muscle attached to the shaft of the maleus, limits movementand increases tension of the eardrum to prevent damage to the inner ear from loud noise.

in english, once or twice maybe okay, but repeated use, will make the muscle exhausted and lose it's tension. what happens if it loses its tension, the hearing bones will engage to your ear drum so now you can actually hear it.

similar system is used in bats where it emits high frequencies for navigation and prey detection system. it unhooks it's staphe from the ear drum while it's emitting high frequencies sound so it doesn't hear its own shriek, thus preventing ear drum rupture.

don't do this to a frog, it will get pissed off if you make loud noise next to it since they do not have system similar to humans or bats. frogs tympanum are larger than human while it has smaller staphe. this is similar to women in high heels, it hurts and it will rupture the drum.

back to original question, "subsonic 9mm out of a 4" or 5" bbl" i still won't remove my ear plug for that one :)

[curt]

Yeeah, i was just going to say something about the staphe...and i did not know that about frogs. You ain't french are you HIPOWER?

[Doc]

lemme cee now, phusiks was back a piece,
bioloiolgy was 'bout then too...
after'n thems came sum long years a skuullin'...

auditory exclusion, one of the byproducts of the stress response aka the adrenaline dump, diminishes one ability to hear and also decreases the perception of the gunshot.

From a laymen's point of view........I simply don't buy the claims I've heard on some forums that LEO's and others can "block" out the damaging effects of gunfire without hearing protection. It is a very real physical thing, not something the mind can mentally block out at will.



They don't block it out, the hearing mechanism is effected by the biological state of adrenaline dump. Try hunting, you will learn something new! Or try a simulation in a shoot house with live fire. After you experience auditory exclusion, its hard to deny its existance.

still the shot will be heard. but the usual effects of ringing associated with loud noises will NOT occur. if you hunt you will have noticed this as well. The only time i hunt with muffs is when I bird hunt because then the gun goes off alot and as the day wears on, aclimation to the hunt and the noise makes the gunfire MORE perceptible.


damage to your hearing is additive and UNAVOIDABLE, which is why shooters use ear protection. over time you kill the cilia in the cochlea, losing the ability to hear high frequency first, then low, the mid range. This happens just during the aging process (see your parents were correct that that fancy expensive stereo DIDN'T sound better, to their ears). If we live long enough, we all get shorter, need reading glasses and have poor hearing.
(Yeah, I know it sucks, but its better than the alternative.)

The process of presbyacoustia is unavoidable.
It need not be gunfire, or even what we consider LOUD noises, just long term exposure to noise over about 80 db which is unavoidable in our society. One of the first thing people notice (no, not the inabilty to hear high frequency) is the loss of "cocktail party ear." (For a full explanation PM)

,,,given the differences between 9mm and 45ACP, they must have different decibel signatures.



Different signatures, sure. Even different volumes (as we understand it as lay people) BUT they are all way too loud. The difference between a jet engine noise (?130 db) and front row rock concert (?125 db) is not preceptible. Above a certain point (db level) the human ear cannot decern a difference, until you reach the threshold of pain (about 140 db).


What hurts your ear in shooting without any ear canal protection are the super compressed airwaves. If you've shot next to anyone touching off .357's, you can FEEL the compression as it buffets you.

The same phenomenon that Tim McVea used to bring down the Murrah building in Oklahoma City, (fuel-air-compressive-explosion) on a larger scale, is the same thing that damages your unprotected ears when firing a handgun.



Kinda.

The level of loudness is NOT the same as the concussion associated with the firing of the gun, or any conventional explosive. It is the firing which creates the overpressure wave which generates both the sound you hear and the pressure you feel, but if you are behind the shooter (say six feet) you don't feel the concussiion, but you hear the shot just as loud. Air can only be compressed so much (that was one of the problems for airplanes breaking the sound barrier).

Can we go back to biology now, please?

[cratz2]

Yeah, none are actually quiet but some are considerably less violently noisy than others. A 230 Gr 45ACP from a 5" barrel has considerably less blast than a 115 Gr +P 9mm from a 3.5" barrel.

And pistols will generally be quieter to the shooter than a pistol, I would think. Gap and all...

Anything louder than a standard velocity 22lr in a rifle is too loud for me.

[Mal H]

" ... quieter to the shooter than a pistol ..."

Cratz2, I think you mean revolver.
;)

[cratz2]

Cratz2, I think you mean revolver.

Well... yeah... you knew what I meant.

With your small font... :p