Suppressors and bullet noise

[DavidAGO]

I spent a couple of hours at our local range yesterday afternoon, and a topic came up in the typical BS sessions that arise when shooters get together. One of the guys there said a suppressor works only at fairly close range, and ony on "muzzle noise". He stated that when you shoot a suppressor-equipped weapon at a target say 50 yards away, the bullet makes it's own noise that is very noticeable and negates the effects of a suppressor.

Of course, not having any suppressor-equipped weapons with any of us, it could not be disputed. So I ask, does the distance you shoot have any effect on the noise that is created?

DavidAGO

[Hkmp5sd]

A suppressor dissipates the muzzle noise of a firearm being fired. Unfortunately, that is not all of the noise associated with firing. If the bullet is supersonic, you will get a very loud sonic crack as the bullet passes your position. If the firearm is semi-auto or full-auto, you will hear the noise of the bolt being slammed back and returning to position. This is why they are suppressors and not silencers.

When subsonic ammunition is used, you will not hear the bullet go by. Depending on your distance from the firearm, you may not even hear the action cycling. A suppressed .22LR Ruger pistol sounds about like a BB/Pellet gun when fired.

[jmorris]

I guess it depends on what you/they mean by “negates the effects”. If the effect you desired was to be able to shoot without ear protection with much less harm to your ears it certainly doesn’t negate the effect. Further, I have shot suppressed firearms around animals an they don’t act the same compared to unsuppressed firearms, in many cases when a bullet impacts around them they look in the direction to access if any threat exists then go back to eating. Repeated impacts will cause alarm (by the unknown) and drive certain animals from an area without spooking other nearby animals. In many states you cannot hunt game animals with a suppressor so, if all you have are deer at the feeder and you intend to hunt hogs in that area you can “run” them off without running hogs into the next county, another benefit. If the impact is pretty large, like a suppressed 500 grain .458 bullet into a rock behind them, they move away from the perceived threat towards you instead of further away. In this instance it could drive the intended target closer thus having a better than negative effect, especially if you are shooting a large subsonic projectile that has a relatively short range. In any (legal) case it can’t make your chances any worse.

[jsykes]

He is likely talking about the sonic crack of the bullet. Any bullet traveling at supersonic speeds will have a sonic boom/crack associated with it that can be quite loud. So its not silent. However, it does mask the direction the bullet is coming from, which is why they are effective in military applications. You do not hear the muzzle blast of the gun, so there is nothing that really points you in the direction of the sound.

Distance has nothing to do with sonic crack.

Distance can come into play with the action of the rifle if its semi or full auto as was said before. The action can be quite loud if right next to it, but will not be heard as you start to move further away. So this might be what he meant when speaking of the distance.

Also, the entire muzzle blast is not necessarily negated, so again, some distance here can be of use.

But all in all they make a HUGE difference and will often allow you to shoot most calibers without ear protection, which is significant.

[DavidAGO]

Thanks for the replies. After reading them, I am not sure about the phrase negating the effects and how he meant it in practical use. However, it does sound like a suppressor does what it is intended to do, mask the noise of a specific shot and make it harder to zero in on the location.

I guess I will just have to make the sacrifice and go back out to the range several times until he gets back and we can discuss it some more.
DavidAGO

[jmorris]

I guess I will just have to make the sacrifice and go back out to the range several times until he gets back and we can discuss it some more.
DavidAGO

You can learn a lot from reading and talking with others the only bad part is you still don’t have 1st hand information and the ability that comes with it. If you are going to “sacrifice” anything I’d say $200 + the device you would like to misspell myths with would be the best start. They will understand in just a few shots.

[RAnb]

Some good info here, I can add a bit more based on my experience with pistol and rifle silencers. A good silencer will reduce noise by 20-30 decibels or more. This is a 100 to 1000 times reduction in noise. This very dramatic reduction in noise can only be appreciated in person as most camcorders and TV/PC speakers are completely unable to reproduce the sound well.

Even subsonic bullets will make a humming noise that can be heard when the firearm is well suppressed. Add in action noise (if not a bolt or single shot) remaining muzzle blast and impact noise, and it is not surprising that some suppressed weapons are still loud enough to damage your hearing, especially when shot indoors or under weather protection.

Suppressed weapons like the 223, 308 and even magnum rifles are still very effective when used with supersonic ammo at long range. The only ones that are only good for short range are those equipped with wipes which slow down the bullet and ruin accuracy.

Silencers do not need to be expensive. I make good ones for $60 and less, plus the $200 tax.

Here is some test data. http://silencertalk.com/results.htm

Ranb

[bcrash15]

Originally Posted by RAnb

A good silencer will reduce noise by 20-30 decibels or more. This is a 100 to 1000 times reduction in noise.

Just so there are no misunderstandings by the OP or anyone else. When he says 20-30 dB reduction, that is a 100-1000x in sound energy, strangely enough (physics is funny sometimes) that corresponds to about a 4-8x drop in perceived volume. So the gun should sound 4 to 8 times as quiet.

[RAnb]

Thanks bcrash15,

Here is a link on decibels and sound pressure levels. http://trace.wisc.edu/docs/2004-About-dB/

Ranb

[Crosshair]

The person you were talking to is correct that the supersonic crack of the bullet is very noticeable. The point of a suppressor is to reduce the muzzle report, thus preserving the hearing of the shooter and masking the position of the shooter.

The sonic crack of the bullet passing gives very little information as to the direction of the shot. The sound of the bullet reflects off nearby objects as well, further masking the direction of the shot.

So while whatever you are shooting at may know it is being shot at, it has no idea what direction the shot came from.

In animals, this results in confusion and the animal generally runs away from the bullet sound, instead of the muzzle report, which ironically can sometimes have them run towards the shooter.

For an enemy soldier, it is clear they are being shot at, but they have no idea where the shot came from, so taking cover is difficult since they don't know what cover is good and what cover leaves them exposed. Instead of an enemy figuring out your location after one shot, it will take many shots to have an idea as to the shooters location and even then it will be a rough guess. By that time there is going to be quite a few wounded.

Take the F-117 for example.

The Iraqis knew they were being bombed in the Gulf War, but they had no idea where the bombs were coming from. If the F-117 was detectable on radar it would have been blown out of the sky. However the stealth of the jet, like the stealth a suppressor provides, masks its position and makes any return fire much less effective.

In Kosovo, through our carelessness and some resourceful intelligence work on the part of the Serbs, they found out where the F-117 was likely going to be and were able to blow it out of the sky with obsolete, though heavily modified, AA weapons.

If you know where something is, then you can destroy it. If you don't know where it is, then it doesn't matter how much firepower you have.

[kiwi56]

A few years ago I was having difficulty sleeping one night when I thought I heard a noise outside. I didn't turn any lights on and saw four guys trying to break into my neighbours car parked in his driveway but obscured from his house. I loaded up my suppressed Marlin 45ACP Carbine and watched these clowns through the scope from a bathroom window, which was in the shadows up the side of our house. Their own vehicle was parked 50 yards down the road with a passenger door left open. With the passenger door open the courtesy light was on so it was eay for me to see through the scope that there was no one in the vehicle or even close to it.
I fired one shot and took out both of the side rear passenger window's. I had already checked the firing zone behind the target and bullet would simply pass into a wooded area. These guys had no idea where the shot came from and were double quick to exit the scene, one even didn't attempt to get back to their car instead he ran straight up the road. I laughed so much that night and then went straight back to bed. Next morning I saw the neighbour when I went out to get the newspaper. he asked me if I had heard anything the previous night then told me to go look down the road where the bgs car had been, there was glass from one side of the road to the other. It didn't just punch a 45 caliber hole in each window as it had obviously completely shattered both windows.