quote:

Originally posted by Bent Fossdal:

quote:

Originally posted by dartfreak8:

quote:

Originally posted by malm:

quote:

Originally posted by dartfreak8:
stop bickering and just buy this brake, it turns off when you are hunting so you don't have to damage your hearing when your hunting..

This line of reasoning has always puzzled me. If the muzzle brake is doing it's job, then wouldn't removing it to go hunting, or, "turning it off" change the point of impact?

the web page says it doesn't and I have tested it out to 200yrds with no change of impact

Huh? Putting a weight on the tip of your barrel will not change POI????

well yea initially it will change it from were it was before installation. But after its installed you can turn it on and off without a change.

If you need a Brake, it is too much gun for you

quote:

Originally posted by MZEE:
If you need a Brake, it is too much gun for you

well there is a difference between needing a brake and liking one. I have no problem managing the recoil of my rifle but I don't mind not having to manage it..

My 300WSM is braked and recoil is like an AR-15. I must also mention it has two recoil reducers in the buttstock and weighs 18.2 pounds with scope and ammo.

It's a bench gun only...

quote:

Originally posted by dartfreak8:

well yea initially it will change it from were it was before installation. But after its installed you can turn it on and off without a change.

So, you tell me that you shoot with a brake on, screw it off and it does not change POI? And this you have checked? And this the makers of the brakes promise?

Well, have not worked a lot with brakes the last 10 years, but I install about 50 silencers every year. I install them with a reaplacement-knob to screw on the threads when the silencer is not in use. And, I have never seen a rifle with the same POI with and without this little knob, wich weighs far less than a brake. Any other gunsmiths opinions on this?

quote:

Originally posted by Bent Fossdal:
So, you tell me that you shoot with a brake on, screw it off and it does not change POI? And this you have checked? And this the makers of the brakes promise?

He was talking about "turning" the brake off, not taking it off. This particular design allows the shooter to rotate the brake to close the ports effectively reducing the noise without removing the brake.

I had said that if the brake were working like it was supposed to, you should see the POI change between brake on, brake off.

quote:

Originally posted by malm:

quote:

Originally posted by Bent Fossdal:
So, you tell me that you shoot with a brake on, screw it off and it does not change POI? And this you have checked? And this the makers of the brakes promise?

He was talking about "turning" the brake off, not taking it off. This particular design allows the shooter to rotate the brake to close the ports effectively reducing the noise without removing the brake.

I had said that if the brake were working like it was supposed to, you should see the POI change between brake on, brake off.

Ah, like the BOSS. Thanks. But, I still agree with you, there should be a change of the POI.

I have brakes on four of my guns. LAR 50 BMG, Encore 510 whisper, Rem 700 338 RUM and a contender in 375jdj. I will not even consider shooting the LAR without the brake. The other three are just more comfortable with the brake, especially the 375jdj. I have a bulged disk in my neck that is slowly resolving itself, it does not like heavy recoil.

If it was not for the law banning silencer use in WA, the 338 and 510 would always be shot with the silencer attached, which in this case works better than the brake

Ranb

quote:

Originally posted by N. Garrett:
The reason you can't use simple subtraction for the combined effects of ear muffs and plugs is that neither one actually reduces sound a fixed amount.

Produce peer reviewed science which demonstrates that a sound attenuated by 10dB when attenuated by a further 10dB is not 20dB down on the sound you started with.

If you can't do that then please stop misleading people on a matter of great importance.

Caorach,

Produce a single article from the medical literature that a shooter wearing muffs and plugs experiences hearing loss from shooting a rifle with a muzzle brake.

You can't.

Garrett

quote:

Originally posted by N. Garrett:
Caorach,

Produce a single article from the medical literature that a shooter wearing muffs and plugs experiences hearing loss from shooting a rifle with a muzzle brake.

You can't.

Garrett

You are absolutely right, I can't, as the medical aspect of exposure to noise is not my field. I have made no claims about the medical aspects of hearing damage.

However, throughout this thread you've been discussing attenuation and decibels as if you know what you are talking about and everything you've said has been misleading and has reflected, at best, a lack of basic understanding, as others have tried to point out. It is important not to mislead people as your misunderstandings could lead to someone deciding not to wear plugs and muffs, for example, on the basis that you claimed that because the attenuations are summed one will become less effective and that there is some "magic" factor in attenuation. The following statement, for example, is rubbish:

"Look on the package of a pair of muffs. Most will have notation of something like "Will reduce sound by 30 dB's".

Now, slip them on.
If you listen carefully, you can still make out (faintly) conversation around you.
Yet if it had actually reduced the sound of normal (human) conversation by 30 dB's, it would have fallen below the thresold of auditory perception."

Normal conversation is usually taken to be about 70dB SPL though clearly it varies and so there are slight differences throughout the literature. There are, as I'm sure you are aware, two ways of measuring the very lowest SPL that the average person can hear: minimum audible field (MAF) and minimum audible pressure (MAP). However, the mean absolute threshold is accepted to be about 6.5dB SPL. So, if you attenuate normal conversation by 30dB you are still experiencing a SPL of about 40dB SPL, in excess of 30dB above the threshold at which you can perceive the sounds. That is why you can hear conversation with muffs on, there is no magic or strange non-linear effect going on.

Should you wish to check on my reasoning then try the following. In the first instance I would suggest you read the Moore book as it provides a brief introduction to decibels, nonlinearity, filters and hearing in general:

Killon M.C. (1978) Revised estimate of minimal audible pressure: where is the missing 6dB? J. Acoust. Soc. Am. 63, 1501-1510

Moore B.C.J. (2003) An introduction to the psychology of hearing. pp. 11

ISO 389-7 (1996)

The bottom line, and I think you have been clear that you agree with this Garret, is that shooters should wear muffs and plugs if at all possible. Where they can use of a moderator is a good idea as well. Use of a muzzle brake can significantly increase the SPL as experienced by the shooter and in that situation even the use of either plugs or muffs may not be enough to protect against hearing loss. Here in the EU there is a recommended maximum level for an impulse type noise of 140dB(C), anything above this will cause damage, and an unbraked 308Win can produce 165dB(C): add a brake and you have even bigger problems.

So, wear all the protection you can get no matter what anyone says on the internet, avoid brakes if you can, consider a moderator and don't go deaf.

Caorach,

Thanks.

You're wrong.

Speech/conversation is 60 db at the loudest end of the spectrum.

You've taken up an alarmist position without the least bit of scientific or medical evidence to back up your hypothesis.

I am sure global warming is a concern of yours as well.

How about ear muffs, a pellet gun, and a bicycle?

All the best,

Garrett

Bent: I once put a brake and open sights on a factory 460 Wby. I was also assigned the job of sighting in the rifle. The muzzle brake moved the poi 8"....yes eight inches at 50 yards! The bullet was NOT hitting the brake, but I finally gave the cusomer a choice...sight it in with or without the brake?

This was not my first experience with POI change, but was certainly the most vivid.

Might be peculiar to the brand of brake??? (Fox River)

Only recently have I had any experience with a brake and equipped my Tikka T3 Tact./308 with one I had custom made. Barrel is threaded from factory and the brake I had made is not of streamlined style, but somewhat larger than the diam. of the muzzle. Brake is very effective in reducing felt recoil and claim was made that the unit would greatly reduce muzzle flip and can say it does indeed work. From prone position the sights, scope or peep, seems to stay right on target greatly aiding in follow up shots. Recoil is more like a "bump" straight back. Accuracy for this rifle is well known as excellent and can see no difference in accuracy with or without the brake and POI is within two to three clicks(.5-.75moa@100yds.) Other impressive feature of this brake is that the flash is at most an orange/red glow and it is contained in the brake body itself which is less than 2" long. Friend of mine has a Mod. 1919 Machine Gun and week or so ago while firing it near dusk, the flash from his gun was about the size of a basket and the same rounds(308)fired in the Tikka w/ brake reduced the flash as described above. As for the sound level, have no idea, but w/ good muffs not bothersome at all. My first experience w/ a brake is a good one and so much so had the same fellow do one for my AR15 rifle w/ equally good results. Recoil about like a 22lr.

Goosehunterjr,

I have only owned a few guns with brakes on them, so I can't necessarily recommend one brand over another for efficiency, but I have made one observation about brakes that may influence your selection. If you intend to shoot from the prone while hunting, do not select a brake that has ports on the bottom. Ports on the bottom are likely to kit up dust and dirt into your face and on your scope when shooting. I have experienced this even when shooting from a dusty, outside shooting bench. I noticed this phenomenon the most when shooting my .300 Weatherby with a factory brake, but also notice it when shooting my .330 Dakota with an SSK Arrestor brake that only has a few holes on the bottom.

I like the Shrewd as sold by Brownells. Comes in many different sizes, in chrome-moly and in stainless. You machine its diameter to fit. The barrel you see below is .992 at the muzzle. I ordered the nominal 1.00 model and had it machined to disappear into the barrel when the barrel was turned by Krieger. I have had them attached to AR-15 bull barrels, too-- after I bought the gun. Just sixty bucks-- for the brake. Machining is extra...

My 300WSM target hog weighs 18 pounds. That's its barrel you see below. With the brake on, it's a joy to shoot. Kicks like a .243 Winchester. Take it off-- it kicks like a mule and jumps four inches out of the front rest. On, the gun shoots less than half-minute. Off, it's a 30-caliber shotgun...

quote:

Originally posted by Duane Wiebe:
Bent: I once put a brake and open sights on a factory 460 Wby. I was also assigned the job of sighting in the rifle. The muzzle brake moved the poi 8"....yes eight inches at 50 yards! The bullet was NOT hitting the brake, but I finally gave the cusomer a choice...sight it in with or without the brake?

This was not my first experience with POI change, but was certainly the most vivid.

Might be peculiar to the brand of brake??? (Fox River)

I doubt it. I took the front sight off a customers gun and his groups went to shit.

Stands to reason that harmonics change when weight is added or removed. A harmonic, like a hormonal, imbalance, throws everything out of whack and therefore everything suffers!

Has it been mentioned that the sound pressure levels double for every 3db increase?

This ugly device cuts recoil and muzzle blast.

quote:

I must also mention it has two recoil reducers in the buttstock and weighs 18.2 pounds with scope and ammo.

...may you need an extra Gunbearer

Seloushunter

quote:

Originally posted by 303Guy:
Has it been mentioned that the sound pressure levels double for every 3db increase?

Intensity is the sound energy transmitted per second under a certain specific set of conditions (measured in Watts per meter squared) and is proportional to the square of the pressure variation. so:

dB = 10log(I1/I2) = 20log(P1/P2)

where I1 and I2 are two intensities and P1 and P2 are two pressures.

Given this strictly speaking a 3dB increase gives a doubling of intensity but a 1.4 (approx) times increase in pressure, to get a doubling in pressure you need about a 6dB increase. So what you are saying is basically right in that you get an awful lot more noise, and potentially damage, for not many more dBs.

dB SPL (sound pressure level) is referenced to 10^-12W/m^2 which is the equivalent of 20uPa and so at 0dB SPL the pressure is 20uPa and at 6dB SPL the pressure will be 40uPa. The intensity will however have doubled to 20^-12W/m^2 at 3dB SPL.

Interestingly if you play people sounds at moderate levels they tend to judge a 50dB SPL sound to be twice as loud as a 40dB SPL sound (1) but when going down they perceive that half loudness corresponds to about 6dB of attenuation.(2) In the end I guess what is important is what people think is twice as loud assuming that we are not considering damaging levels. However, there is a lot of brain work going on in all of this so things are certainly not clear cut.

(1) Stevens S.S. (1972) Perceived level of noise by Mark VII and decibels, J. Acoust. Soc. Am. 51 575 - 601

(2) Warren R.M. (1970) Elimination of biases in loudness judgments for tones. J. Acoust. Soc. Am. 48 1397 - 1413

I have a brake on a 30-06, it is just slots cut on the sides, I think 6 slots, about 1/16 apart IIRC. It blows no gas back that I have felt (haven't shot it in a few years, was supposed to be gunsmiths getting brake cut off but hasn't been finished).

it does reduce recoil, I bought it for my wife, who never shot it. but NO recoil reduction is worth that. I shot it hunting, took hours for my ears to recover and ever since then when my wife is asking me to do somethign I can't hear her.

One thing I would for sure do if you just have to have one. get it threaded on and get a thread protector for in the field. if you have to punish other shooters at the range (being to the side of it when shooting is horrible, the guide was really pissed at me) you can do so. then when you're hunting put the thread protector on instead so your buddy doesn't beat your ass for being inconsiderate.

Red

I have shot several different brands of muzzle breaks.
All of them increase the "noise" to my ears.

The Magna Port, in the field does not seem any louder to me.

It takes the "sting" out of the 300 Win Mag and out of the 375 H&H.

Thanks for that, caorach. Very interesting indeed! Of course, at lower sound levels, the human ear has it's own inbuilt volume control (the hammer and anvil). Apparently alcohol increases noise damage because the muscles that control the hammer and anvil become tired and let more sound through. With gunshot sound, there is no 'volume control' response - no time to react on an impulse.

quote:

... ever since then when my wife is asking me to do somethign I can't hear her.

My device is really just a 'shrouded' muzzle break. The muzzle flash is only visible in total darkness as a dull red glow. I was surprized. Normally one can see the muzzle flash in low light conditions, like before sunset.

quote:

Originally posted by DB Bill:
The VAIS brake is without a doubt the best brake. It is the only muzzle brake I know of that doesn't blast gas back into your face...and the front lens of your scope.

Is very true the vais mazzlebrake is very good, because George Vais disigned it! Ron Bartlett is a crook. Take a look www.vaismuzzlebrakes.com