Do muzzle brakes make a gun more accurate?


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gvnwst
February 27, 2009, 08:35 PM
This thought hit me this morning when i was thinking about muzzle attachments; because gunpowder burns in a barrel/chamber at almost 5 o 6k fps, when it comes out of the muzzle, it is going a lot faster than the bullet. And because it does not burn the same way every time, there are going to be inconsistancies in the "cloud" i thinik, correct? basically, if you have that cloud partially exploding around the bullet, does this effect accuracy in any way? It would seem that if that is correct, then having a muzzle brake would make a fiream more accurate, as it would a large portion of the "cloud" from touching the bullet. Seems suppressors would do the same, if not better. Does this make any sense? (if not, sorry, i am really tired...:uhoh:)

Has anyone experianced this, you had a rifle that you put a brake on, and your groups got even a bit better? But then i see a lot of match guns with 'target crowns", what do these do exactly?

thanks.

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General Geoff
February 27, 2009, 08:58 PM
The cloud of hot gases expanding around the projectile after exiting the muzzle has a negligible effect on the path of the bullet due to lack of pressure.

Grassman
February 27, 2009, 09:01 PM
I just put a muzzle brake on my SKS, we will see.

Duke of Doubt
February 27, 2009, 09:04 PM
Negligible. Waving at the bullet would affect it about as much.

average_shooter
February 27, 2009, 09:04 PM
The crown ensures that the "cloud" you refer to expands at even rates all the way around the projectile. Target crowns are precisely machined.

Put a ding in the muzzle (crown) of a rifle and the gases will exit the barrel sooner at that point then elsewhere around the bullet. This can cause the bullet to get pushed in a different direction. This is also why you should exercise care when cleaning from the muzzle so the rod doesn't screw up the crown.

At least, this is my understanding of it.

Onmilo
February 27, 2009, 09:05 PM
Muzzle brakes make a rifle more controllable on rapid fire and in doing so can make the rifle more accurate in rapid fire.
A muzzle brake will not neccessarily affect acccuracy to the positive in slow fire, it will just make the weapon more distracting to people shooting to the sides of the weapon.

A target crown is a fairly deep recess at the muzzle that is designed to protect the chamfered edge of the muzzle from dents and dings that can affect the bullet flight as the bullet exits the muzzle.

I can best describe a target crown as a counterbore with an outer and inner chamfered edge.

Zak Smith
February 27, 2009, 09:07 PM
The crown is important to the attitude of the bullet the instant it leaves the muzzle. This is also why bullet base defects have a lot more influence on accuracy than tip defects.

You don't see muzzle brakes in bench-rest or NRA long-range matches because they are prohibited by the rules. For bench-rest, this means the best free-market laboratory in which to test accuracy has been eliminated

My experience is that muzzle brakes have a negligible effect on accuracy. They typically increase the shooter's accuracy due to physical and psychological factors.

The same types of arguments you made about brakes have been made about suppressors (silencers), since the bullet exits into a static environment. However, my experience is the same: not sure if weapon accuracy changes, but shooters are typically more accurate shooting suppressed.

moooose102
February 27, 2009, 09:35 PM
i have a mb on one of my rifles. the mb itself had little if any affect on accuracy. my shoulder sincerly appreciated it though. if i were a flincher, it might have made an improvement though. but not a direct physical / mechanical difference.

gvnwst
February 27, 2009, 10:22 PM
Okay, those awnsers are understandable. I guess the taarget crown does sorta the same thing i thought the MB would (control the gases) thanks for explaining that!

beatcop
February 27, 2009, 11:13 PM
The Browning Boss was tunable and had an affect on accuracy, when adjusted, so I suspect that there's more to this. The Boss may have had more of a role in tuning the barrel harmonics than the actual gas dispersion, so the answer still may be no.

owlhoot
February 28, 2009, 01:58 AM
A muzzle brake, flash hider, etc will definitely improve accuracy for any older Ruger Mini 14. the reason is because the Mini barrel is light and whippy and the weight of the brake/flash hider helps attenuate the whippiness of the barrel.

jlg
February 28, 2009, 02:35 AM
lol "whippiness"...sorry that just sounds funny.

The psychological effect of a mb or suppressor will help most people shoot better...it does me. I don't care much for recoil and when I don't have to worry about being mule kicked in the shoulder when I pull the trigger I can concentrate more on the shot and less on "don't flinch...don't flinch...don't flinch..."

I have heard that suppressors generally tighten up groups...although I'm not a good enough shot to confirm that.

Sunray
February 28, 2009, 02:55 AM
No. A muzzle brake does nothing but redirect the gases to reduce muzzle jump and the felt recoil. If a rifle isn't accurate already, a brake, like a telescopic sight, won't make it shoot any better. Neither will a supressor.

m00t
February 28, 2009, 06:28 AM
Muzzle brakes tend to effect a change in the accuracy of a rifle by affecting the harmonics of the barrel, moreso than by evenly distributing the gas cloud during the bullet's exit - that's pretty much what both the crown and compensators do. Thin and light barrels will see more of an effect overall because the greater amplitude of the inherent barrel wobble will be reduced more by the large mass on the end. Even if it doesn't align the wavelength perfectly, which it likely won't (unless painstakingly adjusted), the amplitude of the barrel whip will be reduced. Now then, if you had a very heavy, very rigid barrel, a perfect crown, and a bad compensator, you'd likely see a decrease in accuracy from the comp alone.

Spiffy!

Geneseo1911
February 28, 2009, 09:01 AM
I just want to jump in here and say, "Thank You!" for correctly using "muzzle brake", and not "break". Ohh that drives me nuts. I will resist buying stuff from people who cannot distinguish "break" and "brake".
[/RANT]
sorry, carry on

jwr747
February 28, 2009, 01:41 PM
for my K-31's,I have the screw on brake,of the 3 K-31's,the brake does increase accuracy in one of them.I also have the screw on dampener which increases accuracy on all three.so from my small test.a brake affecting accuracy is a crap shoot. jwr

gvnwst
February 28, 2009, 02:28 PM
I just want to jump in here and say, "Thank You!" for correctly using "muzzle brake", and not "break". Ohh that drives me nuts.

You are very welcome.:D

jwr747--are you sure that it is not just the gun recoiling less, and allowing you to be more accurate? Either way, that is cool.

What exactly do barrel tuners do, i have seen some on BR .22lrs and other target rifles...?

taliv
February 28, 2009, 02:38 PM
Muzzle brakes tend to effect a change in the accuracy of a rifle by affecting the harmonics of the barrel, moreso than by evenly distributing the gas cloud during the bullet's exit - that's pretty much what both the crown and compensators do. Thin and light barrels will see more of an effect overall because the greater amplitude of the inherent barrel wobble will be reduced more by the large mass on the end. Even if it doesn't align the wavelength perfectly, which it likely won't (unless painstakingly adjusted), the amplitude of the barrel whip will be reduced. Now then, if you had a very heavy, very rigid barrel, a perfect crown, and a bad compensator, you'd likely see a decrease in accuracy from the comp alone.

i'm not following you here...

how exactly do you think the muzzle brake affect harmonics?

are you saying the crown and compensators work by affecting harmonics or distributing gas?

rfwobbly
February 28, 2009, 04:23 PM
If by "gun" you mean a pistol, then NO unless you have your rounds loaded way on up there.

If by "gun" you mean a rifle, then I'll stick by this previous reply.....

No. A muzzle brake does nothing but redirect the gases to reduce muzzle jump and the felt recoil.

Hk91-762mm
February 28, 2009, 05:33 PM
The US M-14 National match rifles have the flash hider bored out to a larger diameter to lessen effect on accuracy.
Personal experinace -Sweed M-44 6.5 X55 with the threaded barrell For the blank fire device - I bought a flash suppressof that is after market For the rifle --It really hurt accuracy..

TimRB
February 28, 2009, 05:49 PM
"The US M-14 National match rifles have the flash hider bored out to a larger diameter to lessen effect on accuracy."

The National Match M14 flash suppressors are bored out because they found that the standard ones sometimes fit so poorly that the bullet contacted it on the way out. The boring is not an attempt to lessen the effects of the suppressor per se.

Tim

m00t
February 28, 2009, 06:35 PM
i'm not following you here...

how exactly do you think the muzzle brake affect harmonics?

are you saying the crown and compensators work by affecting harmonics or distributing gas?

From my understanding, the crown and compensators affect accuracy by influencing the way the gas interacts with the round exiting from the barrel. The crown works by controlling the exiting gases in a way to insure that there are no spots where the gas exits in advance of the rest, which would create a region of high pressure to one side of the round. Compensators should work to the same effect, venting the gases directly away from the round in a controlled manner as the round passes the compensator vents. Ideally, no gas would pass the bullet when a compensator is used, but usually this is not the case as they tend to be slightly larger than the diameter of the bore, so most often the accuracy of a compensated rifle comes from the crown anyway.

As far as compensators affecting the harmonics of the barrel goes, any time a weight is added or removed from the barrel (or a pressure point is applied), the vibrational wavelength that the barrel undergoes when firing a round is changed, as is the amplitude to which the vibration occurs. Ideally, to tune a barrel, you want the crown of the barrel to be at a node in the vibration that occurs, so that the rest of the barrel (except other nodes) is moving in space, but the crown remains at a constant position. Since a compensator is essentially just a weight added to the end of the barrel, the position of the crown stays the same, but the wavelength of the oscillations changes, as does the location of the nodes. A crown doesn't have any effect on barrel harmonics, unless you change its location or have to remove a significant amount of material in order to create it.

http://farm1.static.flickr.com/153/336325936_fdd85208c5.jpg

taliv
February 28, 2009, 06:42 PM
np, i think i just misread your post

but given a barrel/ammo combination there's no way to know the node w/o testing, so putting the break on is as likely to hurt as help.

Hans Esker
February 28, 2009, 07:55 PM
Quote from mOOt: any time a weight is added or removed from the barrel ..... the amplitude to which the vibration occurs.
By weight he means mass, BTW.
By adding mass, the amplitude is reduced.

benEzra
February 28, 2009, 08:43 PM
I think the answer may be "it depends."

Some types of brakes can hurt accuracy. The AK slant brake, for example, makes the bullet fly through a several-thousand-mph crosswind immediately after exiting the rifling, and the resulting nutation opens up group size, particularly with hollow-base bullets often seen in eastern European FMJ.

On the other hand, the Smith Enterprises Vortex is commonly said to improve accuracy slightly, presumably by creating a smoother and less turbulent flowfield as the bullet exits the muzzle.

A ported barrel could have some theoretical advantages by bleeding off pressure behind the bullet while the bullet is still in the rifling, but the ports could also shave material off the bullet and make it dynamically or aerodynamically unbalanced, so it could depend on port design.

For most rifles, the difference between a good crown and a good muzzle brake is probably negligible. A good brake might improve accuracy on a rifle with an asymmetrical crown, and a bad brake can hurt accuracy on most anything.

~Eug~2nd1st
February 28, 2009, 09:59 PM
I got an opinion on this... Barrels are accurate for very specific reasons. Real good ones are no mistake and gadgets and gizmos to improve accuracy don't always work. Muzzle brakes, bedding options, free floating, and crowning is an exact science. But the only way to know for sure is testing and shooting...and a lot of it.
However here is my experience. I own a Browning A-bolt 270 with a BOSS adjustable muzzle brake and hunt and shoot quite often with it. When I got it I decided to see what ammo IT liked the best. I don't remember exactly what shot the best but it wasnt the bullet I wanted to hunt with. So after about 40 rounds of expensive 130 grain ballistic silvertips adjusting the brake after every 4 shots, it grouped as good as the heavy ammo that shot best outta the box.
So I don't think the brake made it more accurate, but the adjusting did. Sort of like the way hand loaders fine tune loads and grains to specific guns.
To repeat what has already been said, it is more about barrel harmonics when it comes to brake/accuracy.

oh by the way.. a ported brake like mine takes away most recoil on a 270.
But it makes it loud as Hell... like 300 win mag loud. The improved accuracy is a plus but not near as much as the way that when I shoot a whitetail at 300 yards and make a good kill, three squirrels fall dead around me from the concussion. YUMMY! :D

m00t
February 28, 2009, 10:26 PM
By weight he means mass, BTW.
By adding mass, the amplitude is reduced.

Good call... I meant both weight and mass, actually. Pressure (from weight in earth's gravity, or an upwards pressure point) will change the frequency of vibration, while mass will increase the moment of inertia, lowering the amplitude.

I love physics!

*edit*
Also, Eug2nd1st, that is an astute observation. It is very nice to have a way of adjusting barrel harmonics to compensate for the way different rounds behave during firing. I use a pressure point at the end of my stock, applying a variable amount of pressure to the otherwise freefloated barrel which allows me to tune harmonics in the same way. Spiffy!

Dorkfish
March 1, 2009, 12:14 AM
Some folks from 2 different sniper schools that I've spoken with and served with have given mixed opinions on muzzle brakes and here's why.

Muzzle brakes are intended for multi-shot target reacquisition with speed and relative accuracy. The theory is that with a stable position and proper hold on the rifle, the a braked rifle should return to near the point-of-aim for the initial shot allowing the shooter to set up for a follow-up if necessary. Most small-arms muzzle brakes point upward at angles away from the front sight. No sniper in the world likes to take the 2nd shot as it reveals position. One shot...one kill. Some muzzle brakes are heavy and can result in making a long range accurate shot more difficult than it should be, thus why they usually aren't on sniper rifles with match barrels.

The above theory only applies to lighter small-arms below that of the .50 cal. The muzzle brake on the .50 cal has a secondary purpose...sheer muzzle weight so it helps keep the muzzle down as the rifle begins to recoil. If you look at some of the .50 BMG rifles, specifically the Barrett, McMillan, and now the Bushmaster...you should find that these muzzle brakes do not point up. In fact they should point to the sides and to the rear to help absorb recoil that would normally translate to the shooter. If you've ever fired a BMG, then you know how punishing it is and could imagine how bad it would be without a brake.

Zak Smith
March 1, 2009, 12:41 AM
Some muzzle brakes are heavy and can result in making a long range accurate shot more difficult than it should be, thus why they usually aren't on sniper rifles with match barrels.
No offense, but this is amongst the most ridiculous arguments I've ever heard. The Accuracy International AW .308 brake weighs 3oz. The big .338 Lapua Magnum brake weighs 7oz. For reference an M16A2 birdcage F/H weighs about 2oz.

On a .308 rifle that weighs about 15 lbs, 3 oz is nothing. On a slightly heavier 338LM rifle, the 7oz penalty pays for itself by making the big cartridge's recoil the same as an un-braked .308.

These don't make "long range accurate shot[s] more difficult than [they] should be." In fact, it's the opposite: mass generally increases accuracy due to rifle stability and less recoil due to a brake generally makes the shooter more accurate.


The muzzle brake on the .50 cal has a secondary purpose...sheer muzzle weight so it helps keep the muzzle down as the rifle begins to recoil.
Uhh, no. If you hang a dead weight on the muzzle of a .50 BMG rifle, it will recoil much, much more than an effective muzzle brake of the same weight. Brakes work by gas impacting surfaces more or less "normal" to the gas path and its momentum pulling the gun forward to partially counteract its rearward momentum.

If you look at some of the .50 BMG rifles, specifically the Barrett, McMillan, and now the Bushmaster...you should find that these muzzle brakes do not point up. In fact they should point to the sides and to the rear
The most effective muzzle brakes have structures which take most advantage of the gas momentum. You see this in 3-Gun competition rifles up to .50 BMG rifles. One pattern you see is that the most effective brakes usually have the most surface area "normal" to the bullet path:

http://www.bravocompanyusa.com/v/vspfiles/photos/PRI%20QC%20Comp%2005-0089B-2T.jpg
http://www.jprifles.com/photos_new/JPTRE-5.12S.85_176.JPG

http://demigodllc.com/photo/TRG42AWSM/smaller/D100_3962_img.jpg (http://demigodllc.com/photo/TRG42AWSM/?small=D100_3962_img.jpg)
............... Larger version of above photo. (http://demigodllc.com/photo/TRG42AWSM/?small=D100_3962_img.jpg)

http://demigodllc.com/photo/AI-AW50/smaller/D463_0681_img.jpg (http://demigodllc.com/photo/AI-AW50/?small=D463_0681_img.jpg)
............... Larger version of above photo. (http://demigodllc.com/photo/AI-AW50/?small=D463_0681_img.jpg)

The trend for current and future military sniper rifles is suppressors (which weigh more than brakes). Here's an XM-3
http://demigodllc.com/photo/SteelSafari-2008/smaller/D462_6785_img.jpg (http://demigodllc.com/photo/SteelSafari-2008/?small=D462_6785_img.jpg)
............... Larger version of above photo. (http://demigodllc.com/photo/SteelSafari-2008/?small=D462_6785_img.jpg)

Zak Smith
March 1, 2009, 12:44 AM
Also fact:

The TRG-42 and AI-AW and AI-AWSM sniper rifles are military-issued around the globe, and they come with their respective muzzle brakes.

-z

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