Muzzle Brake bore diameter/accuracy Question

[GAnderson]

Would a muzzle brake for a 6mm bore effect accuracy if it was installed on a .204 barrel? I've read that you want the brake to be around +.020 of bore diameter and obviously the effectiveness of the brake would be diminished somewhat going from a 6mm bullet passing thru versus a 20cal bullet passing thru, but will it also effect accuracy if the bore is oversized? Thanks

Gene

 

[AckleymanII]

Gene, it would not have any effect on accuracy. I use 30 cal brakes on 223's and 6mm's.

Did your 243 come with a large muzzle break?

 

[GAnderson]

It has a Holland brake on it and it is fitted to a Remington Varmint contour 243 barrel...really looks nice, so I have a Rem Varmint contour 20cal blank and was thinking about being able to use it on that barrel as well...whenever I decide what 20 to chamber it in.

 

[dkhunt14]

I look at ot like muzzlebakes are cheap. Usually about 30.00. A muzzlebrake can wear just like a crown. The hot gases can make them get uneven just like the barrel and crown.

Tests have shown on certain guns that the size of the hole has mattered. Maybe not a great amount, but some. Matt

 

[Delfuego]

No, it will not effect accuracy.

 

[tmwinds]

Why would you need a muzzle brake to fire a 30-40 gr. bullet?

 

[LA50SHOOTER]

I agree with the response that "Tests have shown on certain guns that the size of the hole has mattered. Maybe not a great amount, but some"

I'm personally not a big fan of anything screwed on the end of my barrel but in some instances it is pretty much mandatory due to the amount of recoil generated. (Larger calibers - i.e. 50 bmg)

I don't really understand the need for a brake on a 20 caliber barrel. - I'm not a 20 caliber expert, but I've heard they are quite tame as far as recoil goes.

- Ron -

 

[GAnderson]

Why would you need a muzzle brake to fire a 30-40 gr. bullet?

You obviously haven't shot a lot of 20cal variants...have you heard of a 20BR, a 20-250, etc? Even the .204 has a pretty good jump t0 it in the prairie dog fields. Just makes it a little easier to see hits.

Gene

 

[GAnderson]

I agree with the response that "Tests have shown on certain guns that the size of the hole has mattered. Maybe not a great amount, but some"

I'm personally not a big fan of anything screwed on the end of my barrel but in some instances it is pretty much mandatory due to the amount of recoil generated. (Larger calibers - i.e. 50 bmg)

I don't really understand the need for a brake on a 20 caliber barrel. - I'm not a 20 caliber expert, but I've heard they are quite tame as far as recoil goes.

- Ron -

You obviously haven't shot a lot of 20cal variants either...have you heard of a 20BR, a 20-250, 20x47, etc? Even the .204 has a pretty good jump to it in the prairie dog fields. Just makes it a little easier to see hits.

Gene

 

[IdahoCTD]

I look at ot like muzzlebakes are cheap. Usually about 30.00. A muzzlebrake can wear just like a crown. The hot gases can make them get uneven just like the barrel and crown.

It happens a lot faster with the cheaper non-hardened brakes too.

 

[GAnderson]

I agree with the response that "Tests have shown on certain guns that the size of the hole has mattered. Maybe not a great amount, but some"

I'm personally not a big fan of anything screwed on the end of my barrel but in some instances it is pretty much mandatory due to the amount of recoil generated. (Larger calibers - i.e. 50 bmg)

I don't really understand the need for a brake on a 20 caliber barrel. - I'm not a 20 caliber expert, but I've heard they are quite tame as far as recoil goes.

- Ron -

Ron, was it determined that it actually was the hole diameter that degraded accuracy or just the fact that a brake was installed and changed the barrel harmonics...kind of like a tuner? I am reluctant to sometimes want to put things on the end of a barrel too, but more so for the potential harmonic effect, but never really gave the hole diameter much thought because up until now, I have pretty much just had the "right" bore muzzle brake installed.
I guess if someone had installed a brake and got it shooting a "confirmed" accurate load and then opened up the bore diameter and saw a loss in accuracy it would lend itself to this theory...but I haven't run across any info yet that tells of someone doing this. Interesting to know if it as been done though. Thanks

Gene

 

[dkhunt14]

Ron, was it determined that it actually was the hole diameter that degraded accuracy or just the fact that a brake was installed and changed the barrel harmonics...kind of like a tuner? I am reluctant to sometimes want to put things on the end of a barrel too, but more so for the potential harmonic effect, but never really gave the hole diameter much thought because up until now, I have pretty much just had the "right" bore muzzle brake installed.
I guess if someone had installed a brake and got it shooting a "confirmed" accurate load and then opened up the bore diameter and saw a loss in accuracy it would lend itself to this theory...but I haven't run across any info yet that tells of someone doing this. Interesting to know if it as been done though. Thanks

Gene

I remember reading an article about where they took a brake and opened it up more and kept shooting. The accuracy got worse. Some changes werent as bad as others. Cant remember where i read it, but an internet search might find it. Matt

 

[LA50SHOOTER]

Ron, was it determined that it actually was the hole diameter that degraded accuracy or just the fact that a brake was installed and changed the barrel harmonics...kind of like a tuner? I am reluctant to sometimes want to put things on the end of a barrel too, but more so for the potential harmonic effect, but never really gave the hole diameter much thought because up until now, I have pretty much just had the "right" bore muzzle brake installed.
I guess if someone had installed a brake and got it shooting a "confirmed" accurate load and then opened up the bore diameter and saw a loss in accuracy it would lend itself to this theory...but I haven't run across any info yet that tells of someone doing this. Interesting to know if it as been done though. Thanks

Gene

I do believe that the brake hole size will most definitely effect the efficiency of the brake & its ability to reduce the recoil if the hole is oversized,
regarding accuracy, I don't have substantiated proof but I do believe that it can / will effect accuracy. - Also brake hole alignment to bore is critical which I believe can effect accuracy. - The brakes that I have on several 50 BMG rifles are 0.50 over groove (0.500) size. - The most recent Holland's Brake that I provided to the Gunsmith to build (For a .338 cal.) stated to bore the brake hole 0.030 Over bore diameter for the Holland's Quick-Discharge brake (to be installed by gunsmith). - Again, I try to not use muzzle brakes but there are instances where they are necessary due to the amount of recoil. - I'm not a "brake expert" but I know if I eliminate the brake its one less place to have something be that can affect accuracy. - IF they are threaded correct and bored dead-straight I believe they will yield benefits and accuracy will not suffer. Another thing that I'm somewhat "wary of" is reducing the diameter of the barrel too much at the muzzle, I believe turning it (The barrel at the muzzle) down (enough) can cause the bore dimensions to increase ever so slightly (in the ten thousands range) which can't help accuracy at all at the critical crown / muzzle area of the barrel. - Troy Newlon has a publication on muzzle brakes that has some useful information and can help understanding muzzle breaks. - Also, No substitute for precision machine work when the brake is installed.

 

[Ironworker]

On "You Tube" a employee of Patriot Valley Arms say their 30 cal muzzle brake will work perfectly on my 7mm WSM .They said what I really need is the 4 port "Shock Wave" which is exactly what I have.

 

[Delfuego]

I still don't buy it. I run one size up on all my brakes. This give me clearance for all the garbage that builds up in the brake. Never had any accuracy issues and the extra clearance gives me a warm fuzzy.

30 caliber Fat Bastard Brake on a 7 SAUM (5 rounds @ 100y w/ bipod and rear bag).
This same setup stacked 3/3 rounds at 1500y during an ELR match in Wyoming.
RO was impressed and said it was the best group he saw on that target all match.
PS: I am not a great shooter, just had a lucky day...

 

[ND shooter]

Do it again

 

[Delfuego]

Do it again

Ha! I actually texted that photo to my smith and said I should just pull the barrel "cause I'll never do that again". I will be chasing that group till the barrel dies.

My point is that some people seem to be wrapped around the axle on muzzle brake clearance. I have seen at least 3 threads about recently. Not sure why the sudden concern. Definitely develop your load with it installed.

 

[pacificman]

Would a muzzle brake for a 6mm bore effect accuracy if it was installed on a .204 barrel? I've read that you want the brake to be around +.020 of bore diameter and obviously the effectiveness of the brake would be diminished somewhat going from a 6mm bullet passing thru versus a 20cal bullet passing thru, but will it also effect accuracy if the bore is oversized? Thanks

Gene

Seems the best way would be to try with and without the brake and look at your targets for the results
if you can. I feel like you do in the fact that not only the hole size but the weight of the brake might
effect accuracy...hence try it with and without...