Perceived loudness
- Thread starter Tony Z
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RIDE-RED 350r
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DB's and blast intensity are DB's and blast intensity.
Out of equal length barrels, I would tend to think the 38 is going to be more of both than the 22 subsonic. It takes more powder which generates more pressure to launch the larger and heavier projectile of the 38 compared to the 22. And the heavier the bullet, the more powder it takes and the more pressure it takes to still do the job. This is an open ended assumption because you can have different levels of energy between 2 cartridges that propel the same size and weight bullet, example: 30-30 and 30-06. Neither are pleasant on unprotected ears, but in equal bbl lengths the 06 is going to punish you more because it's a higher energy cartridge.
Now, there is one type of shooting I engage in where I usually don't use hearing protection and that's firing a 22 rifle, and it's rare that I do any more. Probably still not advisable though.
However, I use hearing protection when shooting ANY handgun including 22's, sometimes double with heavy magnums.
Your surroundings where you shoot can have intensifying or muffling effects on the level of blast to your ears as well.
And of course when taking your shot at that deer in the field, you don't hear or feel the shot at all!
Game animals make terrific silencers! LOL!
Out of equal length barrels, I would tend to think the 38 is going to be more of both than the 22 subsonic. It takes more powder which generates more pressure to launch the larger and heavier projectile of the 38 compared to the 22. And the heavier the bullet, the more powder it takes and the more pressure it takes to still do the job. This is an open ended assumption because you can have different levels of energy between 2 cartridges that propel the same size and weight bullet, example: 30-30 and 30-06. Neither are pleasant on unprotected ears, but in equal bbl lengths the 06 is going to punish you more because it's a higher energy cartridge.
Now, there is one type of shooting I engage in where I usually don't use hearing protection and that's firing a 22 rifle, and it's rare that I do any more. Probably still not advisable though.
However, I use hearing protection when shooting ANY handgun including 22's, sometimes double with heavy magnums.
Your surroundings where you shoot can have intensifying or muffling effects on the level of blast to your ears as well.
And of course when taking your shot at that deer in the field, you don't hear or feel the shot at all!
Game animals make terrific silencers! LOL!Its the sum of several things all happening at the same instant.
Muzzle blast creates a set of pressure waves, the higher the pressure & the sharper the peak, the louder it seems (Boom Vs Crack).
The bullets size, aerodynamic cleanness & velocity combine to make a "snap", the faster the bullet, the wider the amount of air dispersed & the streamlining (or not) all effect the intensity.
If it's supersonic then you get a sonic boom or several, again depending on the "cleanness" of the bullet & how it pushes air out of the way.
Gun design has a huge effect as well depending on where you are in relation to the muzzle & bore axis. "Breaks" or other muzzle attachments distribute the venting blast in different patterns. Shorter barrels are louder than longer ones of the same caliber, probably because the pressure is still higher as the bullet exits a shorter pipe.
My wife, who is often my spotter swears my .357 magnum 6" is the loudest gun I own. Next is the 7.62 NATO FAL with its "muzzle device", following that is my Jungle Carbine with the short barrel & flash suppressor. Next is the full length No4 Rifle firing the exact same bullet.
Muzzle blast creates a set of pressure waves, the higher the pressure & the sharper the peak, the louder it seems (Boom Vs Crack).
The bullets size, aerodynamic cleanness & velocity combine to make a "snap", the faster the bullet, the wider the amount of air dispersed & the streamlining (or not) all effect the intensity.
If it's supersonic then you get a sonic boom or several, again depending on the "cleanness" of the bullet & how it pushes air out of the way.
Gun design has a huge effect as well depending on where you are in relation to the muzzle & bore axis. "Breaks" or other muzzle attachments distribute the venting blast in different patterns. Shorter barrels are louder than longer ones of the same caliber, probably because the pressure is still higher as the bullet exits a shorter pipe.
My wife, who is often my spotter swears my .357 magnum 6" is the loudest gun I own. Next is the 7.62 NATO FAL with its "muzzle device", following that is my Jungle Carbine with the short barrel & flash suppressor. Next is the full length No4 Rifle firing the exact same bullet.
RIDE-RED 350r said:
I'm not so sure about that. The pressure from a standard velocity .22LR (which, at 1040fps, is still subsonic) is about 50% more than the .38. Because of the greater bore, though, the .38s pressure gets to work on a greater area, so the lower pressure still generates twice the force behind the heavier .38 bullet.
Because of it's pressure, a standard velocity 22LR from a handgun is still plenty loud. My bet, though, is that the .38, fired from a gun with the same length barrel, is going to be a bit louder because while the pressure peaks aren't as sharp (because of the lower pressure), they're a bit taller and broader, so more net noise will hit your ears.
A .308 rifle firing a bullet about the same weight as a .38spl uses about 10-fold more powder than a .38spl in order to get the bullet to a much higher velocity; in doing so, it generates nearly 4 times the pressure of the .38. By comparison, those pressure peaks are going to be very tall and very broad, so a lot of noise will hit your ears.
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A .38 Special will displace more air and cause a louder sonic boom from that air going back from whence it came. You probably wouldn't notice the difference though.
Our perception of noise has more causes than just the sound though. The muzzle blast, the actual amount of air being thrown at your face, as well as the sound waves, alters how a sound is perceived.
Our perception of noise has more causes than just the sound though. The muzzle blast, the actual amount of air being thrown at your face, as well as the sound waves, alters how a sound is perceived.
RIDE-RED 350r
New member
Interesting points MrBorland. 
As dynamic as all of this is due to case capacities, bullet diameters, bullet weights, powder burn rates, firearm configurations, etc etc... it is an interesting question that I have never pondered much till I saw this thread.
Just didn't seem to me that the 22 would peak at as high of pressure as a case firing a larger, heavier projectile.. But what you say about the pressure curve makes sense, similar pressure, shorter duration. But I have to think it is just a coincidence that these 2 cartridges are so close??? I wouldn't even begin to know the std operating pressures of a 22 rimfire. Never had a need to, I can't reload em.
As dynamic as all of this is due to case capacities, bullet diameters, bullet weights, powder burn rates, firearm configurations, etc etc... it is an interesting question that I have never pondered much till I saw this thread.
Just didn't seem to me that the 22 would peak at as high of pressure as a case firing a larger, heavier projectile.. But what you say about the pressure curve makes sense, similar pressure, shorter duration. But I have to think it is just a coincidence that these 2 cartridges are so close??? I wouldn't even begin to know the std operating pressures of a 22 rimfire. Never had a need to, I can't reload em.
Purely subjective experiment: today I fired about 20 rounds out of a .22 LR Henry pump and 20 rounds of a .38 Special load (148 grain WC over 2.7 grains of Bullseye) out of a Henry .357 lever. Subjectively, there was not much difference, though the .38 Special sound seemed an octave lower. The .22 LR was standard velocity CCI.
I'm left wondering how much pressure may have to do with perceived loudness. The .38 Special load is easy to find (around 8,000 c.u.p.). An equivalent value for the .22 seems to elude me! Anyone with some guidance?
I'm left wondering how much pressure may have to do with perceived loudness. The .38 Special load is easy to find (around 8,000 c.u.p.). An equivalent value for the .22 seems to elude me! Anyone with some guidance?