Physics of muzzle brake recoil reduction

[alinwa]

.................... Thats all I need to know. Most every large brake meant for magnums has back rake. They must think it works.

And if this makes you happy then Glory Be....BUT, the title of this thread is "The Physics Of..."

And I never know enough.

As for "They must think it works"......that's exactly right, they mostly do, BUT, today we have the innernet and you can go WATCH guys like me run their tests.

And then you can know.

Or (Lord Forbid!!!) some a you'se guys can run your own tests and share with us?? Confirm or deny instead of just guessing and flanging random "physics" numbers around.

That would be good too!

I have brakes, tests, and the numbers to show and to explain explain how some brakes with zero back-rake beat the fish-gill ones hands down. Go TEST a 30.00 Harrell against anything to be surprised....

GIGO isn't a new concept and any teacher who must resort to numbers and formulae a without clear child-like explanation simply doesn't truly understand the numbers they're applying. For Instance, There are many published explanations of "wind drift" that clearly contradict each other and some folks take this to mean "it's unexplained" or "it's a mysterious subject" or even "opinions vary".......but in reality it's much simpler than that. Some of the published work is WRONG, it's in error. And sometimes a thing can be WRONG but still give rise to "fixes" that work OK in the field.. Case in point. The Marine Corp has been spouting nonsensical "rolling on the wind" and "Magnus" and "Coriolus Effect" to explain "bullet flight" for 50yrs. All WRONG, but still putting our boys hands-on with the gear and dropping bullets onto targets to great effect. You don't hafta' know how to BUILD a racecar, nor HOW IT WORKS to race it!

 

[Alex Wheeler]

And if this makes you happy then Glory Be....BUT, the title of this thread is "The Physics Of..."

And I never know enough.

As for "They must think it works"......that's exactly right, they mostly do, BUT, today we have the innernet and you can go WATCH guys like me run their tests.

And then you can know.

Or (Lord Forbid!!!) some a you'se guys can run your own tests and share with us?? Confirm or deny instead of just guessing and flanging random "physics" numbers around.

That would be good too!

I have brakes, tests, and the numbers to show and to explain explain how some brakes with zero back-rake beat the fish-gill ones hands down. Go TEST a 30.00 Harrell against anything to be surprised....

GIGO isn't a new concept and any teacher who must resort to numbers and formulae a without clear child-like explanation simply doesn't truly understand the numbers they're applying. For Instance, There are many published explanations of "wind drift" that clearly contradict each other and some folks take this to mean "it's unexplained" or "it's a mysterious subject" or even "opinions vary".......but in reality it's much simpler than that. Some of the published work is WRONG, it's in error. And sometimes a thing can be WRONG but still give rise to "fixes" that work OK in the field.. Case in point. The Marine Corp has been spouting nonsensical "rolling on the wind" and "Magnus" and "Coriolus Effect" to explain "bullet flight" for 50yrs. All WRONG, but still putting our boys hands-on with the gear and dropping bullets onto targets to great effect. You don't hafta' know how to BUILD a racecar, nor HOW IT WORKS to race it!

Welcome to accurate shooter. Your BRC attitude wont get you very far here. Anyhow, you are right, I have not done any testing in this area. I dont find brakes to be all the interesting, at least not enough to warrant a test.

 

[IdahoCTD]

Harrell's brakes work good because they have a lot of surface area even though they are 90 degree ports. They fall short on big boomers though. Steep angled ports create more surface area, due to the depth of the port, in addition to redirecting the gases back.

 

[sdean]

I must be missing something. If the side ports don't make much difference then why is a isn't a suppressor a better brake than a brake?

I like reading Al's posts. He takes a little getting used to but he will share his knowledge and uses his real name.

 

[seymour fish]

You skipped 45 degrees backward which is what the most efficient brakes do. Your toupee is fine but the guy beside you hates you. --Jerry

Figured you would be good at interpolation

 

[alinwa]

Harrell's brakes work good because they have a lot of surface area even though they are 90 degree ports. They fall short on big boomers though. Steep angled ports create more surface area, due to the depth of the port, in addition to redirecting the gases back.

I used to believe that, until I actually tested them. (And frankly I didn't even TRY a "wimpy little Harrell-style brake" until about the 6th one, when I had time, because I thought they wouldn't work!) Of course the brake has to be large enough diameter and have enough holes and the holes need be spaced properly. The single most effective arrangement in the smallest length/diameter is one where the holes are drilled off-center forming massive impingement plates in a very small block of cheese....

I build some light 338's designed and built for the 280-300gr bullets, primarily 338-378 Wby's, 338 Lapuas and variants of the RUM case. They kick perty good in a 8-10lb rifle, enough that judging by the recoil sled they'd probably break a collarbone without a brake.

No design can "fall short" if it catches the same amount of gas. In actual fact the same presented area using small holes arranged properly is slightly more effective than widely spaced plates. I think that this is because too large of side openings can actually let pressure bleed off too quickly for it to impinge the plates properly.

I can measure up a brake and then test it and generally SWAG it within 5%

And I've got brakes and shards of brakes scattered for 80yds down my range from making TOO MUCH impingement and not leaving enough metal to take the slap. It takes some strength to reach out and YANK a big 338 back into line.

 

[alinwa]

I must be missing something. If the side ports don't make much difference then why is a isn't a suppressor a better brake than a brake?

I like reading Al's posts. He takes a little getting used to but he will share his knowledge and uses his real name.

For the same reason that your open pickup bed with the tailgate closed doesn't actually knock your gas mileage back like urban legend suggests. When Consumer Reports ran their tests they found that it's no appreciable savings to drop the tailgate......because the air in the bed packs in and stabilizes and forms a "surface" and the air kinda' skims over the surface forming a "boundary layer" kinda like skipping a stone on water. The actual mileage robber is the turbulent vacuum formed behind the square surfaces (like a FB bullet )

A suppressor is a muzzle brake that has to store all the gas before bleeding it off, that's a LOT of gas! So once it achieves an equilibrium, once it's "packed full" (like a pickup bed) the rest of the gases can't impinge the plates....

 

[sdean]

That makes sense. Then the side ports of a brake have more to do with efficiency?
So they do have something to do with reducing recoil.

 

[alinwa]

Welcome to accurate shooter. Your BRC attitude wont get you very far here. Anyhow, you are right, I have not done any testing in this area. I dont find brakes to be all the interesting, at least not enough to warrant a test.

Sorry, guess I shoulda' known better.

I've learned a lot on innernet forums and never once on any forum anywhere have I found "attitude" as you suggest...... differences in presentation? YES. Silly people? YES but generally facts speak for themselves and I enjoy passionate presentations thereof.

And I find myself in fine company....My favorite gun writers are Finn Aagard, Elmer Keith, Robert Ruark, Jim Carmichel, Craig Boddington et al, folks of whom it's been said, to a man, "they don't suffer fools gladly" (which translated into redneck means "they p!$$ people off)

So, on that note.....if anyone really cares, I do have pictures of the single most effective arrangement of impingement plates I've found. my email is alinwa1@hotmail.com

I'll be out of service this weekend camping with over 1000 beautiful people and staying up all night visiting and playing cribbage and telling vast lies.....but if I can find my spam button when I get home I'll try to spam pix to those I can find in my mail....

al


out

 

[savagedasher]

Brake that works the most efficient is one that relies the most pressure off close to the crown Wings that aim backward is veery effective . Brakes with large discharg holes aiming rear word A chamber with large holes is some better Weigh of the tuner mass brakes Helps Tight clearance on the bullet so all the press is discharged out and angled back . Large brakes with big relief are great for recoil But they don't always show good promise with accuracy . Testing on a AR A spiral hole with a chamber brake is very efficient . And tunes easy with a tuner . Clam shell worked better on recoil but never had a good tune
Screw off the clam shell and screw on spiral with a chamber hole it tuned easy install the flashider and it tuned good tuned good with just a tuner.
The best brake I have used is on a muzzload
Shooting 300 gr bullet and 150 gr of powder with a sabot I would say 80% reduction
Larry

 

[IdahoCTD]

I used to believe that, until I actually tested them. (And frankly I didn't even TRY a "wimpy little Harrell-style brake" until about the 6th one, when I had time, because I thought they wouldn't work!) Of course the brake has to be large enough diameter and have enough holes and the holes need be spaced properly. The single most effective arrangement in the smallest length/diameter is one where the holes are drilled off-center forming massive impingement plates in a very small block of cheese....

I build some light 338's designed and built for the 280-300gr bullets, primarily 338-378 Wby's, 338 Lapuas and variants of the RUM case. They kick perty good in a 8-10lb rifle, enough that judging by the recoil sled they'd probably break a collarbone without a brake.

No design can "fall short" if it catches the same amount of gas. In actual fact the same presented area using small holes arranged properly is slightly more effective than widely spaced plates. I think that this is because too large of side openings can actually let pressure bleed off too quickly for it to impinge the plates properly.

I can measure up a brake and then test it and generally SWAG it within 5%

And I've got brakes and shards of brakes scattered for 80yds down my range from making TOO MUCH impingement and not leaving enough metal to take the slap. It takes some strength to reach out and YANK a big 338 back into line.

I build a few brakes too and have tested a fair number of them (including blowing them apart). What I meant is the Harrell's brakes fall short compared to some of the other 4 and 5 port brakes on big magnums. My 4 port brakes are quite a bit more effective then the Harrell's 4 port brakes also but my 5 ports walk away from them.

Port width does change the effectiveness of a brake as does port height. When I built my biggest brake I found that out. I over shot the port width a little and lost some effectiveness on the smaller calibers. The next time I test it will be to find where the larger brake surpasses the smaller ones because on a 338 Lapua (86grs of powder) the smaller one is still more effective. The next step is to test it on my 300RUM with 97grs of R-33 and if it takes more than that I'll test it on my 30-338 Lapua Imp with 112grs of powder. Surprisingly enough it doesn't take much of a magnum to have better results with a 5 port brake. 4 ports do better than 3 port brakes somewhere in the 45-55grs of powder range and 5's do better than 4's in the 60-70gr range.

You can create more surface area with a radial brake but it's a bit dicey trying to keep enough material so they stay in one piece and most people I sell brakes to don't want to shoot a radial brake. There is really no one size fits all brake out there. Tuning port height and width to certain calibers is the only way to go but it would take a massive effort to do so and more $$$ then most people are willing to part with. I think the effort could be worth it for super popular calibers like the 300wm, 6.5 Creedmoor, etc.

 

[bigngreen]

There is a lot going on with port volume and exit pressure as well, I've changed out brakes on rifles and all that changed was the first port volume and it changed how the function worked. There is one guy who has brakes boiled down to an equation and will tune his brakes to a specific chambering for maximum braking. Far more going on than the angle of the ports!! So far the Beast brakes of Nathans have been outstanding on everything I've put them on!

 

[johnfred1965]

There is really no one size fits all brake out there.

So really, we are all right to some extent. Unless you test every brake with every cartridge, you can't really know for sure. Now, can't we all be friends again? Lets use all this bickering against the Libatards instead of between ourselves!

 

[savagedasher]

The question I see it not how efficient the brake is .
But what one doesn't effect accuracy .
Larry

 

[IdahoCTD]

So really, we are all right to some extent. Unless you test every brake with every cartridge, you can't really know for sure. Now, can't we all be friends again? Lets use all this bickering against the Libatards instead of between ourselves!

To some extent, yes. Certain brakes work well on most calibers but that doesn't mean they can't be fine tuned for better performance. I'll do a lot more playing over the next year to fine tune my brakes and work on some new designs.

 

[Ricoanthony16]

I know I'm late to the party but I love physics, am a new machinist, and just got my first rifle. So I have been thinking about making my own muzzle brake.
Here is my thinking :
I want a six side port design (3 per side) with the ports being holes in a semi-circular shape coming away from the bore. I figured a turbine blade design would work best for force transfer and allow the bore to retain as much shape as possible.
I want the port diameter to vary but be no larger than the bore diameter. The goal being to equalize the amount of pressure felt at each port. I think starting small and increasing as pressure drops. Then maybe increasing the length of the side port to increase surface area. Or maybe switching from a round hole an hour-glass shape (dovetail).
I guess titanium is the best combination of strength and weight so I'll use that.
The problem I have is I don't know the pressure the gas creates to estimate wall thickness between ports.
These are just some ideas and would love to hear feedback from others who see the world as a bunch of interacting forces.

 

[onelastshot]

The fact that muzzle breaks direct gases to the side is one of the major issues for shooting in situations where you have fellow shooters to either side of you. Last week I was at the range when another shooter with a break sat on my right side. The gas and noise generated in my direction was so significant that it affected my ability to shoot. They may reduce felt recoil for the owner but the affect they have on fellow shooters is obnoxious at best. If I can't handle the recoil of a rifle I won't shoot it. I wish other would consider the affect breaks have on fellow shooters in a range situation where you have people on both sides of you.

 

[DRNewcomb]

...... I wish other would consider the affect breaks have on fellow shooters in a range situation where you have people on both sides of you.

This is the reason that muzzle brakes are not permitted in most competitions. However, the issue at ranges can be dealt with by range regulations. Just as our club rules require black-powder shooters to move downwind, clubs can limit shooting with muzzle brakes to certain times, places, etc. or just ban them altogether.

 

[onelastshot]

This is the reason that muzzle brakes are not permitted in most competitions. However, the issue at ranges can be dealt with by range regulations. Just as our club rules require black-powder shooters to move downwind, clubs can limit shooting with muzzle brakes to certain times, places, etc. or just ban them altogether.

To me they demonstrate an absolute lack of respect for fellow shooters. People who knowingly shoot at ranges where there will be people adjacent to them are basically saying my comfort is more important then your ability to shoot without interference.

 

[eric32]

Why dont guys that have these issues, talk to the shooter next to you to alternate times.