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Yes, there is some data out there. The difference is very small i.e. 1-2 db. The larger difference was for barrel length. I would also expect that loads vary but I have never seen any published data or heard of anyone testing different loads. It's hard to do good testing of noises that loud and that quick. You need a lot of special gear to do it. A normal noise meter is designed not to measure impulse sounds. They actually average the sound level so impulse sounds are not included in the sound level.
 

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For every 3db you double the sound.
A couple of things that can make a big difference are Porting and shot speed.
Porting isn't necessarily louder but some of the sound is directed to the sides which is a lot louder for those near you.
Once you break the sound barrier (about 1100 fps) you get a big increase in DB.
Here's an article on it:
https://www.americanrifleman.org/articl ... hotshells/
 

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ALL shotguns require hearing protection, (and ported guns are even worse)!

Yes, there are minor differences between the gauges, and by bbl. length, and even fast vs. slow burning powders that don't completely burn within the barrel and are still burning as they exit the barrel! That just adds to the BANG.

I don't believe there are any measurements of all the variables affecting the noise, but it's all damaging to hearing.
 

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Before you can say one sound is louder than another, you have to test at identical distance from the source.

For the shooter, a 30" gun is slightly quieter than a 28" gun because the source (muzzle) is farther from his ear. For a bystander at a constant distance from either muzzle, he can't tell any difference. This assumes the same pressure level shells are fired in both guns.

Sound is just pressure waves traveling through the air. An 11,000 psi load in a 20 gauge will emit a louder sound than a 6,000 psi load in a 12 gauge. It has nothing to do with the diameter of the bore.

What affects how loud your ear tells you something is, is the Sound Pressure Level generated by the source and and your distance from it.
 

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Longer barrels are quieter, not only because they are farther away from the shooter's ear, but also because there is less residual pressure in the barrel when the shot column leaves the barrel. The peak pressure happens before the shot even leaves the shell, but after a few inches of travel, the powder has been burned up and from that point on, the farther the shot travels down the barrel, the more those gasses have expanded and cooled, and the less residual pressure is released when the shot clears the muzzle.
It's a little counter intuitive but given the same shot charge and velocity, the higher pressure load will actually be somewhat quieter than the lower pressure load. A low pressure load uses more of the barrel to accelerate the shot, keeping the pressure on the base of the wad as the wad goes down the barrel and thus there is more residual pressure in the barrel when the wad clears the muzzle and releases that pressure suddenly. It's that sudden release of pressure, not the explosion of the powder that you hear when a gun goes off.
If you really want to see the extremes, compare the sound of a 1 1/8 ounce load propelled by 16 grains of Red Dot to a black powder load that achieves approximately the same muzzle velocity. That Red Dot load will generate around 9000-10,000 psi but it won't be very loud when you shoot it. The ballistical equivalent load using FFg black powder on the other hand will boom very loudly while generating less than 5,000 psi chamber pressure.
 

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Hamltnblue said:
For every 3db you double the sound.
Actually this is incorrect.
3db is about the minimum for a perceptable diffefence in SPL.
10db is generally viewed as a perceptable doubling of SPL.
In the audio world, a 3db increase of SPL requires a doubling of power from an amplifer.
 

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Good question. I'd imagine the best way to measure would be a distance from the ear of a mounted gun to the end of the muzzle.

I once owned a Benelli Supernova with a 14" barrel (I live in Canada, where we can buy them easily). When out hunting without ear pro, the report was so loud that I sold it for a 28" barrelled Supernova. Same gun, same cartridge,...MUCH LESS heard noise.

*Yes, I know I should always wear ear pro, but I'm an old grownup who chooses not to while hunting, Thank You.
 

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Urbansherpa said:
Good question. I'd imagine the best way to measure would be a distance from the ear of a mounted gun to the end of the muzzle.

I once owned a Benelli Supernova with a 14" barrel (I live in Canada, where we can buy them easily). When out hunting without ear pro, the report was so loud that I sold it for a 28" barrelled Supernova. Same gun, same cartridge,...MUCH LESS heard noise.

*Yes, I know I should always wear ear pro, but I'm an old grownup who chooses not to while hunting, Thank You.
There's more to it than the distance from the muzzle to the ears. The sound of a gun is not the sound of gunpowder exploding, it's the sudden release of the residual pressure in the barrel when the shot column leaves the barrel.
The powder burn is over in milliseconds, before the shot even clears the shell, from that point on, you basically have an air rifle with the pressure of the hot gasses continuing to accelerate the shot and while doing so, they expand losing both pressure and temperature. If the barrel is long enough, the pressure is nearly zero and the gun is very quiet, like when shooting standard velocity .22 LR ammo out of a 26" barrel rifle. Shoot that same ammo in a 4 inch pistol barrel and not only do you need hearing protection, but so do people who are next to you.
That characteristic "whip crack" noise made by a .22 rifle shooting high velocity ammo is not muzzle blast, but the noise made by the bullet going faster than the speed of sound. With target ammo, which is intentionally loaded to sub sonic velocities, all you hear is the muzzle blast which is very mild out of a long barrel.
 

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lowgun said:
My .410 Cutts guns are louder than any non Cutts guns when fired with my preferred competition loads.
The old club I shot at most when I lived in Canada had noise complaints from folks who'd recently moved into the area, bought a 5 or 10 acre lot on which to build a retirement property and they didn't like the sound of shooting in their locality. We were subjected to all kinds of noise pollution assessments by a department (can't recall the fancy name they went under now) of the nearby township who knew zip about shooting. To assist them in their noise tests we all turned out periodically and shot some skeet. We decided to use our .410s. Mine had a Cutts on it and I was soon told my contribution wasn't required :wink:. We eventually lost the battle and the club closed down. How sad is that?
 

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A 3 db difference will double the sound intensity and 10 db difference will double the loudness.

Barrel length and devices such as cutts compensator and porting do not increase the sound level, they just redirect it. The sound level is caused by the explosion and the only way to reduce the sound is to baffle it in what we call a "silencer".
 

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ceh383 said:
Hamltnblue said:
For every 3db you double the sound.
Actually this is incorrect.
3db is about the minimum for a perceptable diffefence in SPL.
10db is generally viewed as a perceptable doubling of SPL.
In the audio world, a 3db increase of SPL requires a doubling of power from an amplifer.
3db is double the sound. Look it up.
Formula is db=10 log (power out/power in)
I used to teach it
 

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Hamltnblue said:
ceh383 said:
Hamltnblue said:
For every 3db you double the sound.
Actually this is incorrect.
3db is about the minimum for a perceptable diffefence in SPL.
10db is generally viewed as a perceptable doubling of SPL.
In the audio world, a 3db increase of SPL requires a doubling of power from an amplifer.
3db is double the sound. Look it up.
Formula is db=10 log (power out/power in)
I used to teach it
While the formula is correct, human hearing does not always hear it that way.
A 20hz tone at 93db would not be heard as twice as loud as 20hz at 90db.
Now some might hear a 93db tone at 12,500khz as twice as loud as that same 12,500khz tone at 90db.
My comment was based human hearing, not the math behind it. Much of how we perceive sound is based on the individual and the frequency of the sound.

What is the frequency range of a shotgun blast?
Is it the same for all guages?
This may account for the differences in perceived loudness...
 

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Very few people can actually hear a 20 Hz tone, unless it has a lot of harmonics due to distortion (clipping), in that case it's the harmonics you hear, sort of like a higher pitch that's interrupted 20 times a second.
12.5 KHz is also on the upper bound of hearing for the average middle aged adult.
Putting it into perspective, the E string on a violin vibrates at 660 Hz. If you stop it one octave up, (the pinkie finger in the third position will play that E) you get a 1320 Hz tone. Go one octave higher, (now you're about an inch from the end of the fingerboard) and you get 2640 Hz tone.
 
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