Difference between a suppressor and a silencer?

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Plenty of other suppressors on the market are hearing safe.
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Maybe if you shoot sub-sonic ammo.

You will NOT find a "hearing safe" suppressor for the .223.
The sound that is most harmful to your ears is the "crack" from the bullet exceeding the speed of sound.
Same reason why hearing protection is required when working in the pits, pulling targets, when the shooter is distant 200 yards or more.
No suppressor/silencer can reduce that "crack."
 
I'm quite familiar with suppressors, sound testing, and suppressor design. My company makes sound suppressors.

No, you are wrong, there are plenty on the market that reduce the sound signature below 140dB with supersonic ammunition, which is the OSHA threshold for impulsive noise. AAC currently has all 6 of their 5.56mm suppressors that reduce the sound signature well below 140dB. My company has both 5.56mm suppressors below 140dB. GemTech has all 6 5.56mm cans meeting or exceeding OSHA level. I can't think of a company whose can doesn't suppress less than 25dB with their 5.56mm suppressors. So there's over two dozen suppressors that are hearing safe. That's only three companies and there are dozens out there. If you like I can find more to list.
 
I don’t about all of the numbers but I have shot 22lr rifles (I plug for .22 pistols) most of my life without “ears” unless I was indoors or around others that might shoot something louder around me. All of my suppressed rifles and pistols with the exception of one are just as quite as a .22 rifle, most make less noise.
 
You will NOT find a "hearing safe" suppressor for the .223.
Click to expand...

I can make any suppressed firearm (even with 1000 fps ammo) too loud to shoot without hearing protection just by shooting it in an enclosed space. The environment a person shoots in is a big deal. While shooting my 338 ultra mag with a can out in the open is hearing safe (as far as I can tell), even something much less powerful like the 223 rem is not hearing safe if shot under weather protection outdoors. The muzzle blast and sonic boom reflect off of the weather protection and hurts the ears.

My hearing is tested periodically. I can still hear as low as 5-20 decibels depending on the frequency. I never shoot without hearing protection of some sort, either plugs or a silencer or both, even when sooting a rifle with 22lr subsonic. The only ammo I have used that is hearing safe without a suppressor is the 22 CB in a rifle.

Ranb
 
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"Silencer" is the correct term.....as defined by the inventor and classified by BATF. Many use the term "Suppressor" which is fine.
 
I always wondered: What if your rifle had a barrel that was so long that the gas completely finished expanding before the bullet left the muzzle?
Theoretically speaking, it would be "silenced" but it would not have a silencer.
Anybody know how long the barrel would have to be?
 
Here is how I determined it. From my reading, it seems that when smokeless powder chemically decomposes to a gas, it expands by a factor of 1700 times the original volume, not including the change in temperature. The temperature climbs to about 5000 degrees F. If 25% of the heat is lost through the barrel and we convert to Rankine, then the final temperature is 4120 R If we start with a .308 caliber barrel and 50 grains of powder with a volume of 3.6 milli-liters, the gas expands to about 6120 milli-liters (373 cubic inches). A 30 caliber barrel with this volume is 417 feet long.

To correct for temperature, we use the following equation;

P1V1/T1 = P2V2/T2

Initial Temperature is 68 F or 528 R Assuming that initial and final pressure are the same, final volume would be equal to T2V1/T1, or 417 x 4120 / 528 = 3254 feet long.

I'll stick with using a silencer.

Ranb
 
Basic high school physics/math. The US Navy made me use it again in school.

367 feet long for a 22lr barrel. Actually I think there is no way the bullet would ever make it out of the barrel given the amount of friction there is in there. I think it would stick in less than 50 feet and the remaining pressure would slowly leak out past the bullet and the brass case.

Ranb
 
I always wondered: What if your rifle had a barrel that was so long that the gas completely finished expanding before the bullet left the muzzle?
Theoretically speaking, it would be "silenced" but it would not have a silencer.
Anybody know how long the barrel would have to be?
Click to expand...


Here is a design that is based on such a concept:

http://www.dillerdesign.com/quietgun/
tomanddeer.jpg
image001.jpg


Shotguns of course operate at much lower pressures, meaning you start closer to where you want to be, but there is also a significant volume of air offsetting that somewhat, and a larger caliber bore for sound waves to exit.


This thing is basically a very long barrel with ports that allow small amounts of gas out along part of the length.
By the time the majority of the gas reaches the muzzle end it has slowed so much that the noise level is very low.


Here is some noise levels of a standard 12 gauge by barrel length:

12 Gauge
28" barrel 151.50dB
26" barrel 156.10dB
18" barrel 161.50dB

The decibel system is logarithmic, 10 decibels higher is 10x more powerful for example, roughly twice as "loud", and has well over 3x the pressure wave on average.

As you can see just 10 inches of shotgun barrel alone reduce the decibels by 10.
An 18" barreled shotgun can be twice as "loud" as a 28" barreled shotgun using the same ammunition.

Now consider that the ATF considers any device you add to the firearm that reduces the muzzle report to be a "silencer".
Just barrel can reduce the report by more than that. Even a fake suppressor, those plain tubes that are added for appearance should reduce it by that much. Meaning by their own definition a fake silencer is a silencer.
(But those are widely sold as a cosmetic accessory.)


Obviously a long enough barrel can reduce the report significantly.
The problem with RanB's example is that is assuming you need to get to air room pressure. But you don't need to get to anywhere near that pressure to have something as quiet as a typical silencer.
You can have a report closer to a typical pellet gun at a fraction of the length required to return to normal air pressure.
Though the length is still obviously cumbersome and typically impractical.
 
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What reduces recoil?

If I am not trying to silence a rifle, but to reduce the recoil, what is the name of that device? It blows some of the blast out to the sides or rearward.
 
It is a muzzle brake. Providing a surface for the gases to push forward against and diverting the flow to the side or back reduces recoil. It can also greatly increase noise heard at the shooter's position.

Ranb
 
A silencer/suppressor serves quite well as a muzzle brake, too.
That was one of the advantages cited by Mr Maxim in 1909. The Army thought so, there was a plan to issue silenced Springfields to marksmen. The reduction in noise, flash, and recoil would make them effective. The plan fell through against obstacles of bulk and cost, and the then new emphasis on long range machine gun fire.

NRA does not allow suppressors in F class shooting on the grounds that they are effective brakes and give a competitive advantage. I knew a couple of guys who shot with them before the ruling and they seemed effective. Not so effective on blast that you could get along without ear protection, though. You don't shoot subsonic at 1000 yards. I stood behind one of them and took out my earplugs. It was still too loud for comfort. The whistle as the "can" depressurized after each shot was a surprise.
 
Hi Ranb:
Thanks.
Do you know if there are any instructions out there for making such a thing?
I have looked at pictures, and wondered if such could be put on a rifle.
I don't think they are illegal, are they?
 
Hi Jim Watson:
I saw that Maxim photo down lower, but silencers are illegal.
So I wanted to avoid going to prison just to reduce recoil.
Thanks for your response.
 
Silencers are restricted but not illegal in most states. There are tons of plans out there for making your own.
 
First Big Foot. You need to take a look at the CA statues to see if putting a muzzle device on a rifle is legal. It might just be the barrel threads that are forbidden. It might only apply to semi-auto rifles. Threading a barrel and attaching a brake or flash suppressor might make it an "assault rifle".

Wahoo95, I think when FBF says silencers are illegal, he means in the PRK, CA to the rest of us.

Ranb
 
my definition is that its a silencer if its subsonic and I dont need an ablative to assist quieting. That basically covers only .22 rimfire, 9mm and the precious few 40 and 45 dry cans like my SilencerCo Osprey. Anything going supersonic which includes all centerfire rifle cans like .223 and .308 are suppressors. Also all wet cans in 9mm, 40 and 45 that need an ablative like pulling gel or water to be hearing safe I deem a suppressor. Of course even the quietest .22 rimfires arent truly silent by definition, but they come close with the right host like a .22 bolt gun.
 
Here is how I determined it. From my reading, it seems that when smokeless powder chemically decomposes to a gas, it expands by a factor of 1700 times the original volume, not including the change in temperature. The temperature climbs to about 5000 degrees F. If 25% of the heat is lost through the barrel and we convert to Rankine, then the final temperature is 4120 R If we start with a .308 caliber barrel and 50 grains of powder with a volume of 3.6 milli-liters, the gas expands to about 6120 milli-liters (373 cubic inches). A 30 caliber barrel with this volume is 417 feet long.

To correct for temperature, we use the following equation;

P1V1/T1 = P2V2/T2

Initial Temperature is 68 F or 528 R Assuming that initial and final pressure are the same, final volume would be equal to T2V1/T1, or 417 x 4120 / 528 = 3254 feet long.

I'll stick with using a silencer.

Ranb
Click to expand...

Just to make a couple theoretical adjustments without doing the math - you're going to dissipate a lot more heat with a long barrel, and gases cool as they decrease pressure, so the actual length of the barrel needed would probably be somewhere in between the two numbers you gave.
 
Silencer, means you are watching a movie
suppressor, means you are IRL

there is no such thing as a silencer that I am aware of, a suppressor is a muzzle device that suppresses the sound coming out of the muzzel... but it is most definitely not silent
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This has been debated to death. The terms mean the same thing. Look at AAC's website. They are one of the top makers and call their's "silencers".

AAC website
 
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