Sound level question

[AJC1]

The muzzle pressure needs to be factored. The breech pressure may be 58,000 psi for any loads compared, but the muzzle pressure can vary significantly, and this is the pressure level that is popped off into the atmosphere to generate the sound level. This isn't a function of the bullet mass per se, but it depends on the powder burn rate and progressivity/digressivity, and of course on the barrel length. Generally speaking, if you want the quietest load while still having good penetration, go with a heavy-for-caliber bullet, load it with a fast-burning/digressive powder, and shoot it out of a long barrel with no muzzle brake, port or compensator. It will not be hearing safe, but it could be several decibels lower.

The heavier bullet will use less powder to achieve the same 58,000 MAP and therefore the muzzle pressure will be lower and the sound level lower.

That formula results in exactly as you describe a lower sound signature, it also results in a reduced power level and despite the desire of the op I prefer to put Mister make me a snack out of commission

 

[drband]

The difference in decibels between a .32Long and .44Mag is fairly insignificant - 152.4 vs. 164.5 dB - so the argument about more powder or bigger blast doing more damage doesn’t hold much water, either. Maybe that’s just a matter of perception or the mind playing tricks on the senses but a less than 10% (12.1 dB) delta is not significant. Again, I really think the OP would benefit from a consultation with a real, trained medical doctor of audiology. Internet wisdom - even from me! - isn’t going to be useful.

db scale is logarithmic. 10 db difference is 10 times louder. 20 db difference is 100 times louder.
.44mag is at least 10 times louder than .32swLong

 

[westernrover]

Reduced power level is not the same as reduced effectiveness. We know this from defensive handgun use against human attackers and it is well documented. Increasing the blast, gas, flash, and recoil to 11 isn't the formula for effectiveness. Once you penetrate through and through, the bullet isn't doing more damage once it leaves the target, and placing subsequent shots on target is going to do a lot more additional damage than a little more velocity on the first bullet.

Admittedly, tuning the load just for sound level isn't going to get the best result either. We need to have a goal velocity for a given bullet that we can have confidence will achieve sufficient penetration and expansion if it is designed to do so.

If we can meet the goal velocity for a given projectile, and thereby infer sufficient penetration, then "more" is no longer better. If we can achieve that goal velocity with different loads, we can select the load that meets ancillary goals like lower sound levels, etc.

 

[N555]

The muzzle blast difference will not matter, in the sense of hearing loss.

The high pitch scream of seeing the bear attack will be much more damaging and the actual bear getting ahold you could result in total hearing loss.

That's dark. Really dark.
I like it.

 

[tmd16556]

Once bears enter the picture everything goes crazy. I’m convinced it’s a corollary to Godwin’s law for shooting forums. Once bears get involved…

 

[AJC1]

Once bears enter the picture everything goes crazy. I’m convinced it’s a corollary to Godwin’s law for shooting forums. Once bears get involved…

I thought the final answer was always a glock 20... I kinda felt any 6" magnum was fine. The more North you are the bigger the bore.

 

[GeoDudeFlorida]

I thought the final answer was always a glock 20... I kinda felt any 6" magnum was fine. The more North you are the bigger the bore.

Back in the old Lee-Enfield forum days (RIP Mark) there was a cadre of Canadian posters who were very generous with their knowledge of the subject and history of the Empire. One was a teacher on Baffin Island who wrote about various aspects of living that close to the Arctic Circle. One was the antics of white bears. The Baffin Islanders used 38mm (1-1/2”) rubber bullets to discourage the bears from going through dumpsters and helping themselves to the contents of grocery stores shelves. Four or five good thumps with hard rubber bullets would send the bears packing without hurting them. Every once in a while one would get upset and they would have to resort to gas canisters but that stank up the whole town so it was avoided.
For reference, a direct hit at close range from a 38mm rubber bullet can be fatal to a human. That’s why their use is limited and pretty much discouraged.
Bears. Why did it have to be bears?

 

[Demi-human]

Since this is a revolver, with gas escaping from the cylinder gap at full throttle in each loading, the simple answer is, no.

Worse yet, the gas comes from a very small aperture, making the screech horrific on hearing.

I use daily, for work and play, Walkers VX3s. (Inner ear infections as a kid killed my hearing and many sounds hurt.)
They have 32NRR, with amplified ambient sound as well as Bluetooth enabled connectivity. Megadeth at work, Mozart at the bench. Power boost for hunting, so I know when to make fart jokes to squirrels.
My second set. Not cheap, and well worth it!

I would like to try the cordless ear bud ones next.
I have not researched their NRR, but I don’t wears any ear buds now because none of them on the market have a significant Noise Reduction Rating, though many boast of how much their buds are able to do the damage themselves…

 

[Double Naught Spy]

No, but now that you mentioned it haha

Was just interested in what load would have the most impact energy with the least noise if I were to carry the 500 4” in the mountains.

This statement reminded me of discussions form 20 years ago about how people would be looking for defensive handguns with contradictory criteria. They wanted the lightest gun carrying the most ammo with the biggest caliber to do maximum damage with the least recoil. So you want the quietest 500 ported 4" that is the most effective against bears.

I assume your S&W 500 4" also has a muzzle brake to go with the cylinder gap. You aren't going to be able to attain your goal of trying to preserve your hearing, plain and simple and while you might be able to reduce the damage slightly, sort of like having 63% of your house burn instead of 65%. Whatever slight changes you make to the loading aren't apt to make any practical real world difference, particularly after you fire your 3rd or 4th shot. I would contend that if protecting your hearing is critical, that this is not the gun/caliber configuration that is right for your needs.