Sound Redirector


PDA






eocoolj
March 30, 2013, 07:36 PM
I wasn't sure where to put this, but figured the NFA guys would know best... I was reading this recent post on the firearm blog (http://www.thefirearmblog.com/blog/2013/03/30/simplistic-shooting-solutions-qd-brake-shield/) about how some muzzle brakes result in a much louder shooting experience for the shooter and/or those around him. The question is, has anyone ever built a device designed to do the opposite? I'm talking about something that wouldn't suppress the sound, but just redirect it downrange? Could you design something that would meaningfully reduce the amount of blast experienced by the shooter, without venturing into NFA territory? I would assume that such a device would have no value as a muzzle brake by the time you were done with it.

If you enjoyed reading about "Sound Redirector" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!
BK
March 30, 2013, 07:43 PM
http://noveskerifleworks.com/cgi-bin/imcart/display.cgi?item_id=kx3556p&cat=141&page=1&search=&since=&status=&title=

MasterSergeantA
March 31, 2013, 03:21 PM
Levang Linear Compensator

http://www.brownells.com/rifle-parts/barrel-parts/compensators/levang-linear-compensator-prod5594.aspx

JustinJ
April 1, 2013, 12:32 PM
I don't believe any such device would lower sound to safe hearing levels. I also don't see how a device could direct sound forward and still dampen recoil. Muzzle flip yeah but not recoil.

MasterSergeantA
April 1, 2013, 01:24 PM
The OP wasn't specifically asking about reducing the sound "to safe hearing levels", but just how to direct more of it downrange, unless I misread the post. And I believe you are correct. I would also agree that such devices would probably not reduce recoil...and might actually increase perceived recoil as compared to a muzzle brake.

But a number of folks have reduced the effect on other shooters around them by using the Levang and other devices. I know that the brake on my Barrett gets the attention of anyone standing to the left or right when I fire. Directing the sound downrange would be most easily accoplished by removing the brake, but that would (I am guessing here) probably increase the amount of recoil passed along to the shooter.

Krusty783
April 1, 2013, 03:41 PM
You have to think about the sound of a gunshot as composed of the initial muzzle blast which is followed by the sonic boom of the [supersonic] projectile. The perception of the sonic boom is limited to the cone of influence (aka cone of silence, mach cone), which is defined by the local speed of sound and the projectile mach number.

The muzzle blast can be thought of as dropping a stone in a pond. The resulting ripples will propagate outward and reflect off of any surface they encounter. If you have a plain muzzle, this acts as essentially a point source. If you have some type of flash suppressor or brake, the expansion happens at the cutouts in the device as well as at the end.

Well, the device as illustrated in that blog post is essentially like the first stage of a suppressor because it provides an initial expansion volume for the muzzle blast. If you extend that cavity forward a few inches and add some baffles --- Abra Cadabra, You just manufactured a suppressor!!
[knock, knock] Sir, This is agent ?%^& with the $%^"@! :eek:

The gap in the device illustrated is what makes it different than a flash suppressor or muzzle brake. The gap allows for some initial expansion, which is then directed downrange by the shield. It's basically the Krink and Linear Comp taken to the next level. I'd imagine that next level is a gray area between NFA Land and non-NFA Land, or we would be seeing more of these devices.

A muzzle brake has surfaces which direct the compressed gas (and it's expansion) rearward or laterally, before it's introduced to the atmosphere and allowed to expand.

I'm just an aerospace engineer, but I would be hesitant to publicize that particular device within earshot of any upwardly mobile federal agents...

JustinJ
April 1, 2013, 05:26 PM
The OP wasn't specifically asking about reducing the sound "to safe hearing levels", but just how to direct more of it downrange, unless I misread the post. And I believe you are correct. I would also agree that such devices would probably not reduce recoil...and might actually increase perceived recoil as compared to a muzzle brake.

Yeah, i'm not sure either what the goal is. If not to reach safe levels then i'm not sure what the point is. To me, either you have to wear HP or you don't but i guess maybe down to a point where just ear plugs are sufficient with the larger calibers?

MasterSergeantA
April 1, 2013, 05:52 PM
That might be it. It would certainly reduce the need for HP (to some degree) off axis so that other shooters are not as inconvenienced. The shooter also would perceive a lower level of noise, although not enough to warrant leaving the ear plugs at home.

Darkbob
April 1, 2013, 06:10 PM
I have read that the Linear Compensators and the Noveske Pig are reported to reduce shooters perception of the sound of the shot. That made me wonder about leaving a Golf Ball Launcher (http://www.amazon.com/NcStar-AR15-Golf-Launcher-AGOLF/dp/B003ELMSFC) on a rifle while shooting live rounds. In Iowa, us normal citizens aren't allowed to own suppressors, so something legal that may help maintain my hearing is worth looking into.

NOTE: The launcher is not a silencer! It just looks like one from the sides and back.

I'd think that because of it's length the launcher would direct a lot more of the noise forward, away from the shooters ear. But, what do I know.

MasterSergeantA
April 1, 2013, 06:14 PM
I'll have to look at my golf ball launcher, but I'm not sure the opening is large enough to allow a round through. They are, after all, made to function with blanks only.

But I agree with your thinking.

MrCleanOK
April 3, 2013, 08:22 AM
Krusty,

The Noveske KX3 is blessed off on by the ATF. You don't see a lot of them because they're expensive, heavy, and really only useful for SBRs that don't have sound suppressors to go with them.

Dustin0
April 5, 2013, 12:35 PM
I have the Levang Linear Compensator on 7.5inch SBR. It does help you can shot it without hearing protection with it being painful but not suggested. Standing next to someone firing the gun will loosen your fillings. So they kinda work. But it will work till I get a can.

jmorris
April 5, 2013, 12:47 PM
I have the Levang Linear Compensator on 7.5inch SBR. It does help you can shot it without hearing protection with it being painful but not suggested.


Just reading that aggravated my tinnitus.

FIVETWOSEVEN
April 5, 2013, 01:42 PM
I have read that the Linear Compensators and the Noveske Pig are reported to reduce shooters perception of the sound of the shot. That made me wonder about leaving a Golf Ball Launcher on a rifle while shooting live rounds. In Iowa, us normal citizens aren't allowed to own suppressors, so something legal that may help maintain my hearing is worth looking into.

What I've thought about is something like the golf ball launcher that is really long (bench rest applications only) that is long enough to let the gas expand within the tube. There are extensions for shotguns that thread into the choke threads that add another 7 feet to the barrel but it's dead quiet.

Sam Cade
April 5, 2013, 01:50 PM
Ive got PWS dogknots on a couple subcarbines and shooting them without the core installed does make them less blasty.

JustinJ
April 5, 2013, 04:12 PM
There are extensions for shotguns that thread into the choke threads that add another 7 feet to the barrel but it's dead quiet.

Feet or inches?

Darkbob
April 5, 2013, 05:12 PM
What I've thought about is something like the golf ball launcher that is really long (bench rest applications only) that is long enough to let the gas expand within the tube. There are extensions for shotguns that thread into the choke threads that add another 7 feet to the barrel but it's dead quiet.

Feet or inches?
It does add feet to the barrel.

The shotgun barrel extension I think FIVETWOSEVEN is talking about is the Quiet Shotgun (http://www.dillerdesign.com/quietgun/index.html) by Diller Design. And Yes I'd be interested to know if it would work for a rifle also. I'd guess that the biggest problem with making something similar for a rifle is that with the smooth-bore shotgun, the tube is actually a barrel extension. But with a rifle, I don't think (i am not a machinist or gunsmith) you could make an actual extension due to the grooves in a rifle barrel.

IF you could just get a lightweight, 3 foot long, screw on, muzzle adapter to put on a rifle, at the very least the sound impulse would start 3 feet further away from my ears, even if the actual decibel level at the end of the tube is the same as before. Which it really shouldn't be, since the gas has time and room to expand and lose pressure.

FIVETWOSEVEN
April 6, 2013, 02:21 AM
Feet or inches?

Feet :)

I figure it could be big enough where the bullet never touches the extension. I'm game for someone to create one as an experiment.

Darkbob
April 8, 2013, 10:27 AM
That's kind of where I think the NFA issue would arise. I think that the Quiet Shotgun is only ok because its a barrel extension, just taken to extremes. Now, it is definitely there with the sole intent to reduce the noise, but I think the reason it's legal is because it is just making the barrel longer.

Adding a tube that is definitely NOT the barrel, for the sole purpose of reducing noise, may get into the NFA territory, I don't know.

Longer barrels are OK, but devices to reduce noise are not.

I'd be curious to know what the ATF would say to a rifle flash hider that has an inch or even just a half-inch diameter opening (for .223 caliber), but extends out 2' from the end of the barrel. No baffles or end cap, just a tube.

I haven't done the math but I'm assuming that the volume in a tube that size would allow the gasses to expand enough that the pressure would be significantly reduced by the time they reach the end.

If you enjoyed reading about "Sound Redirector" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!