Two brake questions.

The design of muzzle brakes is very interesting to me, and a concept was offered to me in the goal of reducing the back blast or concussion effect of your typical muzzle brakes.
I took the reigns and printed a line of brakes, (which original started as one). The first thing that is noticable is the first port being 90 degrees and the remainding ports angled toward the shooter, other things went into the design that help them do what they do well, which I tend to keep to myself. As you can see from the video on my product page the blast is directed too the sides and at a very high velocity comparred to other brakes. No concussion or back blast is felt by the shooter.

Sound testing of a Muscle braked 7rum to a non braked 260 remington netted a DB reading of 122.4 to 119.6 respectfully.

Kevin Kram of Montour County Rifles, and Ron at Benchmark barrels can attest to their performance.

These brakes have no "expansion chamber", each baffle is .020" bored over bullet dia. I have found this design the most effective style of brake.

The 338 WSM handgun in the video did have a JP brake on previous to the muscle brake and the customer and his son reported better recoil reduction with the muscle brake.



http://www.centershotrifles.com/sales/img/CSR_MuscleBrake.jpg

http://www.centershotrifles.com/sales/

Customer testimonial.

Hello Jim,

I recently purchased and had your muscle brake installed. I put the brake on a savage model 12 in .270 wsm. Prior to the install there was no way to shoot this rifle with free recoil as it had fairly sharp and quick recoil with some muzzle jump as well. It was just a bit more than I wanted to hang onto for extended range time.

Since the brake install the rifle is definitely a “pussycat” to shoot and easy to control with the added benefit of no backblast whatsoever! I have fired other rifles equipped with muzzle brakes but most had an unpleasant backblast which in itself can lead to a dreaded flinch. Now becoming comfortable with this rifle has led me to a .194” group on my second 3 shot load development. Thanks again for a well designed product that actually does just what it was supposed to do with no hype whatsoever.

Cordially,
Chris P.
 
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Al, the theory of the brake acting as a sail and pushing the gun forward to counteract the recoil generated by the accelerating bullet is flawed. I'm not sure how it was perpetuated but it was'nt on sound reasoning or testing. A simple experiment in any ones shop proves it invalid.
 
I have read the brake deflected the flow of gases going straight out the barrel and in doing so disrupted that thrust effect and reduced recoil. I have also read the weight of the gases being 'caught' by the brake reduced the recoil.

Please explain your experiments and conclusions. I know brakes work, I have not come to a conclusion why.
 
An air hose left wide open on the shop floor at 200 psi. will push and wip the hose oposite the direction of air flow.

Attach a 2"x2" block of wood, steel, aluminum, ect. perpendicular to the air nozzle, 1" in front of the nozzle attached to it with two connecting straps.

If the sail theory were correct you would see the block nozzle and hose shoot acrost the shop floor in the same direction as the flow in the hose(forward). It dose'nt happen.
(the hose may jump a little bit due to the air deflected 90 degrees and then acting upon the concrete floor)

Now drill a 1/2" hole in the block and again the hose will move rearward to a slower more controlled level than the wipping hose as in the first sentence above.
 
Put thia way, ist obvious, thanks Jim.

But how does it work then?

I mean, recoil isn´t only from gases pushing the gun back.

So........I´m confused?
 
The hardest guns to control recoil on are 1st heavy bullets. It is by all means near impossible to remove the recoil created by the accelarating/moving solid/tangible mass.

2nd. large bores, because more of the "jet" "thrust" effect follows the larger bored hole that accomidates bullet clearance.

Combine both and you have a difficult rifle to control recoil. add to that a low pressure chambering and it becomes % wise a harder gun to reduce recoil on.

What the brake does is deflect that "jet/thrust" by directing it to BOTH (or 360 degrees) dependent on style) sides were it then counteracts itself. (if we sent it out one side our rifle would atually kick to the opposite side throwing you off target by 60 degrees.) what is left to produce the recoil is the mass of the bullets acceleration in the bore and that gas which follows it thru thre clearance holes.

Now rearward angled brakes actually use the "jet /thrust" effect to counter act the recoil by redirecting the jet of gas rearward thus creating a forward thrust, this effect is relativly small probably extreamly small in most designs but may contribute to an increase in percieved recoil reduction of 3-8% depending largly on design aplication and cartrige.
 
Sound testing of a Muscle braked 7rum to a non braked 260 remington netted a DB reading of 122.4 to 119.6 respectfully.
Click to expand...

This doesn't sound correct..........3dB is the least amount of volume change a human ear can detect. I have to believe redirecting the gasses would have to yield a much higher increase in SPL to the shooter. It is extremely difficult to measure the sound from a muzzle brake compared to an un-braked rifle. The muzzle brake acts sort of like a "Flute" and changes the sound frequency dramatically. You would need an ultra wide band sound spectrum analyzer and a microphone that could handle the pressure generated to measure it.............Otherwise the measurement will just "top out" the microphone and all the readings will be at the limit of the microphone........

I have read the brake deflected the flow of gases going straight out the barrel and in doing so disrupted that thrust effect and reduced recoil.
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In a nut shell.........this is how brakes work. The sail analogy is akin to mounting a fan on a sail boat and having the sail catch the wind and move the boat...other than a bit of redirected "spill" off the sail, the boat ain't gonna move....although it is done on Saturday morning cartoons all the time..... :)
 
RoyB said:
I have read the brake deflected the flow of gases going straight out the barrel and in doing so disrupted that thrust effect and reduced recoil.

In a nut shell.........this is how brakes work. The sail analogy is akin to mounting a fan on a sail boat and having the sail catch the wind and move the boat...other than a bit of redirected "spill" off the sail, the boat ain't gonna move....although it is done on Saturday morning cartoons all the time..... :)
Click to expand...

In the past I have 'explained' to customers the reason a larger diameter brake is more effective is because the ports are longer with more 'jet effect' of the gases to the side... maybe I am right... :)
 
Dennis Sorensen said:
In the past I have 'explained' to customers the reason a larger diameter brake is more effective is because the ports are longer with more 'jet effect' of the gases to the side... maybe I am right... :)
Click to expand...

you are, A small dia brake creates more of what I call a hand grenade type explosion the burst is more radial than directed, that gas that blast forward has less effect on recoil reduction. In the Muscle brake video of the 7mm dakota you can see that the gas has a definite direction created by the function/design of the brake, that day was 100% humidity and the moisture condenses is the gas plume showing exactly where it is going.
 
RoyB, I borrowed a sound meter from a audiology dept at a local clinic rated for 140 DB. I positioned the meter in 3 diferent locations during testing to compare locational effect and the meter functional showed a 3db+/- .5 dbs difference in comparable locations. When used in my shooting house with the barrel out the window the effect was an additional 2db with both guns but still about a 3db spread. I'm not saying this was absolute top end equipment, I'm sure it wasen't. I did give it enough of a try to believe the relationship from one to the other was sound. In the vidio of the 7 dakota you will notice I forgot plugs in the first shot. The effect was a very short term ringing. Much less than when I made the same mistake with a Shrewd brake. And far less then when someone shot a browning boss with out a general warning to his friends some years ago. I am also not sure if sound db scale is linear or compounding which could make 3 db a large change.
 
I'll let Jim have this thread.....;) not because I agree in any way with the whipping hose as a metaphor for how a brake works, but because his brakes DO work well and because he's got a business interest involved.

To those for whom the whipping hose works, voilahhhh...... you've got your answer.

To those who'd like to know more about how brakes work try the search function. There's very little accurate information on the web regarding this subject and very nearly all of the brake mfgrs have it wrong when they try explain it. This doesn't change the fact that the brakes work, well.

This argument is kinda' like arguing with a Marine gunny about bullets "rolling on the wind." I say, give it to gunny! It works....

al
 
Just remember that the dB scale is logarithmic -- a 3 dB increase is a doubling.
Correct! You have to double the amplifier power to perceive an audible difference. A 100 watt amplifier is only 3dB louder than a 50 watt amplifier............barely louder to the human ear.

3dB is the smallest change in amplitude the human ear can detect.................An increase of 10dB is approx twice as loud...........
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Click to expand...
 
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Awwww, I just can't let it completely go :)

About the whipping hose.....

Put a great big ol' fan on a ship and blow it at the sails!!!!

Does it go?

LOL

al
 
All brakes in use by me have the holes angled forward slightly at 7 1/2 degrees and the edge of the hole that faces the shooter cut further at 30 degrees for about 100 thou. This reduces the blast at my head considerably compared to a 90 degree type brake and still reduces recoil by an estimated half. I've got one conventional 90 degree brake that I used at two matches. Both times it knocked my hat around and produced substantial retinal bleeding in my right (shooting) eye, the one that had cataract surgery a couple of years earlier. Couldn't see a thing for three days and it was three weeks before I lost that looking through a dirty aquarium effect. Just in time to do it again at the next months match. More than a hundred matches with the angled brakes has never provoked bleeding. I'm done with 90 degree brakes.

FWIW

Greg
 
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alinwa said:
Awwww, I just can't let it completely go :)
About the whipping hose.....
Put a great big ol' fan on a ship and blow it at the sails!!!!
Does it go?
Click to expand...

Of course it goes. The sails can't catch all the air movement the fan creates. Just because it moves silghtly backwards is not an issue in your post.

@Roy

Yes, 3dB is generally taken as the just noticeable difference point -- when we're talking in a very general way about using the ear as a measuring device, and the signal is white (or is it pink?) noise. It's been a long time, but as I remember, the response curve is not linear, and changes rather dramatically with age. Finally, the ear has a "compression circuit" -- the muscles that preload the eardrum. It is a pretty complicated system.

As far as why we care: perceived loudness is one issue. Damage is a different one.

Edit:

BTW, in this case, the scale should probably be dB-SPL There are about 10 of them as I remember . . .
 
alinwa said:
Awwww, I just can't let it completely go :)


Put a great big ol' fan on a ship and blow it at the sails!!!!

Does it go?

LOL

al
Click to expand...

Which direction does it go? I don't think it would blow boat ahead but it also would not be very effective in moving the boat backward...

???
 
Dennis Sorensen said:
Which direction does it go? I don't think it would blow boat ahead but it also would not be very effective in moving the boat backward...

???
Click to expand...
A better analogy to this might be:

Stand in a little red wagon and throw a bowling ball out the rear of it. The little red wagon goes forward. Now, stand in the same little red wagon and throw the same bowling ball with the same force, but this time, have someone else (also standing in the little red wagon) catch it. The little red wagon goes forward for a while, but soon comes back to a stop. Now, to closer represent what happens in a gun, you throw 4 or 5 bowling balls and have the other person only catch one. The wagon does not go as far with the person catching one. (1 ball = muzzle blast gas = propellant mass).
 
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