I figured this might be the best area in which to post the following.

With some of the discussion about muzzle brakes on the big game forum I wanted to post some information from the A-Square reloading manual concerning muzzle brakes. I think the third paragraph should be of particular interest.

This is found on pp. 174-175. Hopefully that gives them proper credit for the following information.

Here goes:

A muzzle brake is a device mounted on the muzzle of the rifle which (upon passage of the base of the bullet past the gas port holes in the barrel) directs expanding and escaping powder gases to the rear. By definition, the gases must be directed to the rear. If they are directed to the side, the jet effect of the gases does nothing for the reduction of recoil. It may do something for the reduction in rise of the muzzle (and thereby, on a poorly stocked rifle, reduce the blow to the cheekbone) but it does nothing for the total recoil effect.

Anywhere from half to three-quarters of the recoil of any rifle is generated by the bullet exiting the muzzle. There is absolutely nothing that can be done about this recoil. It is a fact of life. The remainder of the recoil is done by the jet effect of the exiting gases. Any gas which is directed to the rear decreases the mass of the gas jetting forward from the muzzle. The re-directed gases also pull the rifle forward by the gas pressure on the forward vanes of the muzzle brake. If you can re-direct half the gases, you are decreasing the gas jet effect component of recoil by one-half. You are further subtracting from the recoil of the rifle (based on the efficiency of the muzzle brake) by the weight of that gas times its exit velocity times a factor for the angle of the exiting gases. A muzzle brake can reduce the actual total recoil impulse by as much as 15% to 20%, which will be perceived as a reduction in recoil on the order of 20% to 30%.

However, a muzzle brake makes an extremely significant increase in the over-pressure and noise at the muzzle of any firearm. Recorded noise levels (on certified audiological instruments) at the muzzle of a magnum or high velocity rifle with a muzzle brake normally exceed 160 decibels. Permanent ear damage occurs at 120 decibels. If you read the fine print on the finest set of ear plugs and ear muffs available, you will find the total noise reduction only between 22 and 31 decibels. This means that on a rifle with a muzzle brake, even if you are wearing hearing protection, you are suffering permanent ear damage. This is, of course, to say nothing about the ear damage caused to the others around you, such as your partners on the skeet squad, or your tracker or PH out on safari. Even if you don't care about yourself, a muzzle brake causes permanent ear damage to those people. Even if you don't care about them, you should consider the decrease if effectiveness of a PH whose ears are ringing like sirens when he is trying to track a wounded animal.

As a responsible firm, with a solid engineering background, the A-Square Company cannot and will not ever place a muzzle brake on a firearm. There is no question that permanent hearing damage will result. There are a number of other firms coming to the same conclusion. Starting in 1995, literature from some PH's in Tanzania, Zimbabwe, and Botswana has clearly stated that if a client shows up in camp with a rifle with a muzzle brake, he must either dismount the muzzle brake, use another rifle, or be sent back to the airport. I believe this policy will become widespread.

******

It would be interesting to have some decibel readings for non-braked rifles vs. old style brakes vs. the new Vais type brake. Perhaps we could put this subject to rest once and for all??

Food for thought.

Reed

Written well before the VAIS brake was developed.....although George Vais has done some tests on his brakes (showing as I recall about a 2 to 3 db increase) those who have their minds made up won't be convinced.

I've run my own tests the hard way spending my own money....had one of the brakes with "many little holes" similar to the Answer brake on a .300 WinMag and although it did reduce recoil and muzzle lift, the additional noise (and direction the noise was generated) made it almost impossible to shoot at a public range without getting extreme dirty looks and nasty comments....however, the part I hated most was the blast of exhaust back into your face every time you pulled the trigger...talk about inducing a flinch.

I tried a Vais brake and the difference was like night and day...no more dirty looks from near-by shooters and more importantly, no blast of exhause back into my face.

I now have Vais brakes on both of my hunting rifles.....the Lazzeroni Patriot and the Lazzeroni HellCat.

Others may scoff and be skeptical but I've done the test and the Vais brake has passed.

I wasn't necessarily being skeptical. I probably should have mentioned that the Vais type brake is considered to be considerably less noisy. Nevertheless, it would be nice to attach decibel levels to a given rifle unbraked, Vais-braked, Answer-braked, and clam-shell braked.

I'm usually against new "rules" but it sure would be nice to do away with the noise makers...at least at a given club's discretion.

Reed

I would totaly disagree with the theory of the gas having to travel back to make a brake work.

Like stated above, the Vias brake does not do this. The Answer brake noted above does not either. The holes in the brake are drilled at an 11 deg forward angle, and they are probably the most effective brake out there. At least when it comes to recoil reduction. The Vias is quiter and does a fine job with recoil too, but not quite as effective as the Answer brake in recoil reduction.

I have a decimeter and would like to measure them as well. The only brakes I have on any rifles right now are Answer brakes, but I may be buying a Vias soon, as my supply of Answer brakes is dwindling and I most likely will not be doing any business in the future with Answer.
I was head smith there for 3 years and quit. I am now opening my own shop in late August. FFL already aproved by the ATF and waiting on zoning.

I have shot both brakes many times.

Celt H.D. Rifles

[ 06-14-2002, 04:49: Message edited by: Celt ]

Another thing that makes a brake effective is an expansion chamber.
A well designed muzzle brake will have an expansion chamber with in it.
An expansion chamber is always in the first part of a brake, it is usually thread diameter and is from 1/2" to 1" long from where the actual rifles muzzle is. The brakes exit hole is then reduced to a few thousands over bore diameter. The gas expands in the open area behind the bullet, then is forced up against the front walls of the chamber and out vent holes in the chamber then thru the exit hole and out vent holes in the exit hole area. The slaming of gas against the front of the chamber and vent holes pull the barrel forward as recoil is pushing it back. Plus the 90 deg. dispertion of gas causes a reduction in felt recoil.
This makes for much more gas venting, thus reducing far more felt recoil than a brake with out one..

I am not sure decibel readings are very meaningful when "hurt factor" is the problem.

Generally large bores, including shotguns and muzzle loaders seem to make the most noise when decibels are measured, at least when measured some distance back from the gun. But they don't have the "hurt factor"

I agree with DB Bill on the hot air coming back. I had that witha 416 Wby. I felt like I was in the pits at the speedway

Mike

If one were to were the foam ear plugs and muffs over the top of that would that make brakes safer on your ears??

Okay, can one of you smart guys tell me where a person could buy... or even just rent... a sound-measuring device? I mean, to check a scope's brightness, you can use a lightmeter. I'm sure there are "noisemeters," but I doubt that's what I'd call around and ask for.

Russ

PC,

I have little rubber plugs. They sort of look like those insulators on a telegraph post. Under the muffs they will cut the noise a lot more. They are also good at the range when shooting abig kicker as often you rifle causes your muffs to lift a bit when you fire, and just at that time the bloke next to you lets go with his 243.

Mike

Inexpensive sound pressure measuring tools will NOT give accurate readings of what is essentially impulse noise. Don't waste your time and money on trying to rent the right tools; all rifles will damage your hearing-- some just more than others.

And in any case, the numbers wouldn't mean much in the context of hearing damage. Damage isn't linearly correlated with the SPL, I believe.

As for A-Square's claim about brakes that don't vent backwards not being able to cut recoil, that's pure BS.

The gas is initially moving forward. Some force changes its direction of travel to perpendicular to the bore. That force has a component that's back toward the shooter. Net effect is that the gun is forced forward by that acceleration of the gas.

They are correct in that side-vented gas cannot compensate for the recoil caused by the bullet. Backward vented gas can do that to a substantial degree though. (For the physics-inclined, think perfectly inelastic collisions-- the gas coming straight back will cause twice the momentum transfer into the gun, relative to going forward. )

As with the belief that milling flutes into a barrel will make THAT BARREL stiffer, this "side vented gas can't reduce recoil" business is simply not true.
Pertinax

First off, the primary factor in recoil is not the bullet exiting the muzzle, but the expansion of gas inside the barrel (for every action there is an equal and opposite reaction). Not that this matters so much when talking about a brake. The force of gases exiting the muzzle is more than Asquare stated, with the energy being a function of the square of the velocity of the gas times the mass of the gas. What makes the new brakes so effective is the slowing of the gases on exit. A brake with an expansion area works well because the gas also expands to a volume with the square of the radius of the chamber, reducing the mass exiting the barrel over a given segment of time. So you have the square of two parameters working for you with a modern brake, which adds up in a hurry! Also the expansion of gas before exiting the barrel also helps reduce the peak decibels. Just a tiny bit of theory.

The National Firarms Act of 1938 got it backwards -- muzzle brakes should be registered and taxed and suppressors should be encouraged. This is one area where the Brits are way better off than the Yanks.

Most muzzle brakes are about equal as it is merely a displacement of gas..the bigger the brake the better it works..I usually pick the one that is the least offensive in looks. the only way to make on quiter is to make it less effective in the recoil dept., simple logistics...

I like them on big bores that tend to loosen my fillings and blow the Copenhagen out of my mouth and plug up my scope lens.

Hi Gang.
The device you're looking for is a Sound Pressure Level Meter (SPL Meter). Most devices that won't be destroyed trying to measure greater than 150db are NOT inexpensive. Audiocontrol, out of Mountlake Terrace, WA offers a real time analyzer (spectrum analyzer) with a 'blast mike' microphone upgrade so it will register up to 180db. Last time I checked, it cost around $1800. You might be able to find one used, but make sure to send it back to the manufacturer to be recalibrated!

Russ - are you anywhere near a major military installation with a firing range? If so, contact the local military health facility and ask if they have an audiometry unit in their preventive health section. I used the one here at Wilford Hall to measure increased hearing damage risk from shooting our MP-5s and M-11s in the shoot house, that freed up some money for good hearing protection... If there's one of these near you, you might sweet talk them into coming to the range with you (I had to shell out a couple boxes of ammo and a 30 minute lesson on how to shoot the MP-5, well worth it).

Good luck!

Kevin

One thing to remember is that a measurement in decibels represents the logarithm of a ratio of SPLs (sound pressure levels). Thus, a 3 db increase actually represents a DOUBLING in the loudness of the sound (i.e., it is twice as loud). A 3 db increase is not a small change in loudness.

Regards, Wayne E.

I have about as much use for muzzle breaks as I do for a bout with the flu. I advise against them.

They are ugly, they weaken the structural integrity of the rifle, they are a nuisance to clean, and - most important of all - they are a threat to your hearing and to the hearing of others. If recoil is THAT much of an issue, take a step down in caliber, install a better-designed stock, or else spend more time in practice at the range.

AD

Allen,

Normally I would be saying "yeah, you tell 'em" as I've been "against" the use of muzzle brakes for as long as I've had a worthy(less) opinion. I couldn't agree more that if a person "needs" a muzzle brake they'd be better suited to drop down in caliber. Two things, however, are on my mind at the moment.

First, the Vais brake is very intriguing to me as it seems to be well received by several folks for whom I have great respect. G&G in Colorado makes a similar device and I thoroughly enjoyed speaking with the man that ran that shop.

Second, I came into a 338/416 Rigby that weighs 13.5 pounds. I enjoy the concept with that caliber but at that weight it's just simply too light to shoot more than 5-10 rounds (off the bench that is). Holding it like it were a hunting rifle it's not too bad but that's not for what it was designed.

I could try to add a bunch of weight to the stock, I've even looked at metal stocks, but that Vais brake installed for $160 is damned attractive.

Nevertheless, the point of my original post was to discourage the use of brakes in general other than possibly the Vais as it appears to have some legitimate claims to recoil reduction without drastic increases in noise.

Reed

Reed....you had better be careful. Be willing to try something that O'Connor or Keith didn't espouse can put you on shaky ground...you don't want to be accused of having an opne mind do you?

You can be so very open-minded that all of your brains fall out........

AD

I think we have it, my brains fell out after shooting the unbraked 338/416...I know my ear plugs have been kind of greasy and I no longer get headaches. I guess I'm too open minded.

Actually, I may swap some barrels around and rechamber that 338/416 to something with a smaller case, for hunting. Then I may do a heavy weight long range rifle of some sort using the 338/416 equipment I now have. I'm still thinking.

OUTLAW BRAKES (Muzzle, that is)!!!!!! There, is that better?

Later,

Reed