Muzzle Brake Torque Affect Accuracy?

[Thebelly]

My Search-fu sucks today. If you know where there is an established thread on this, please help me out.

How much (if at all) can the torque of a muzzle brake affect the accuracy of a semi-auto .308? Can the design of the brake also affect this?

Gun: Larue PredatAR 16" 7.62
Brake: Surefire MB762SSAL/RE (the kind that overlaps the barrel a bit)

Thanks in advance for all the help!

 

[Lowlight]

It can, if you over do it, it can effect the exit of the bullet.

That said, so can the design of the brake, as well as the tolerances of it.

I have seen issues with SF brakes in the past where it's a bad build and the brake will screw with the accuracy. Helped with a CS issue with an AI AE, the gun was sub MOA (3/8) without the break, put the brake on, it went to 3/4, but the can on it went back down to 1/2MOA. The initial thought was torque but that turned out to not be the issue and it was something with the brake.

It seems to be happening more and more with SF lately like they changed something or who ever is building them, but I have seen it myself in person and it's not the gun, torque or threads, that only leaves one thing.

 

[samnev]

I have 2 SF 308 SOCOM brakes on my rifles and the accuracy (group size) hasn't changed but the sure reduce the felt recoil. Just don't get me started on the timing shims being out of tolerance and the nightmare to get the timing right.

 

[ORD]

Brakes, flash hiders, suppressors, etc., can and do have effects on accuracy in a number of different ways which can be either positive or negative, and not just based solely upon how they are torqued (under-, over-, or properly to spec) on the barrel. Any number of factors can impact accuracy any time you start doing anything to the muzzle of a barrel, including but not limited to whether the barrel itself is properly threaded (not just correct threads cut to spec, but also whether the barrel is threaded concentric to the bore). Furthermore, different muzzle devices can impact barrel harmonics, bullet flight, etc. Just by virtue of adding even a slight amount of weight that some brakes add (some more than others) can have an impact on accuracy thanks to barrel harmonics/whip/etc. Furthermore, going back to brakes...some tend to collect carbon build-up moreso than others which can impact accuracy if its allowed to accumulate without intervention.

Similarly, the same can be said for a suppressor, which can also effect accuracy...especially dependent on its mounting/attachment method, weight, etc. There is no one, simple, universal truth that muzzle brakes/suppressors do or do not effect accuracy, but the potential to have an impact on it is there and will vary wildly.

As to your specific rifle/brake combo...only you can tell that tale with any meaningful input. Run it with the brake off and with the brake properly installed with the Surefire recommended 20-30ft/lbs and note any discrepancies. YMMV!

 

[Thebelly]

It can, if you over do it, it can effect the exit of the bullet.

That said, so can the design of the brake, as well as the tolerances of it.

I have seen issues with SF brakes in the past where it's a bad build and the brake will screw with the accuracy. Helped with a CS issue with an AI AE, the gun was sub MOA (3/8) without the break, put the brake on, it went to 3/4, but the can on it went back down to 1/2MOA. The initial thought was torque but that turned out to not be the issue and it was something with the brake.

It seems to be happening more and more with SF lately like they changed something or who ever is building them, but I have seen it myself in person and it's not the gun, torque or threads, that only leaves one thing.

Have you seen these issues with this particular brake?

I'm not discounting the loose nut behind the trigger.

 

[pupdawg]

Have you seen these issues with this particular brake?

I'm not discounting the loose nut behind the trigger.

The best way is to test fire a few groups with the brake on and off. See if there is a measurable difference. Same load, same day, same everything just with the brake and then with the bare muzzle.

Run maybe 4/5 FIVE shot groups with it on and off.

BTW what kind of group sizes are you getting?

 

[Thebelly]

The best way is to test fire a few groups with the brake on and off. See if there is a measurable difference. Same load, same day, same everything just with the brake and then with the bare muzzle.

Run maybe 4/5 FIVE shot groups with it on and off.

BTW what kind of group sizes are you getting?

With the factory installed A2 birdcage, somewhere south of 3/4". Now, maybe 2".

I haven't yet done the direct side-by-side test.

 

[sinister]

Excessive torque with any muzzle device can cause a trumpeting of the muzzle and wreck your precision.

National Match M16s will have flash suppressors mounted with the old peel washers, timing the top slot to top dead center, then blue Lok-tited on.

 

[Thebelly]

I'm busy at work this weekend, so I'm not able to get to the range. ugh!

 

[Thebelly]

Excessive torque with any muzzle device can cause a trumpeting of the muzzle and wreck your precision.

National Match M16s will have flash suppressors mounted with the old peel washers, timing the top slot to top dead center, then blue Lok-tited on.

I've changed to a flash hider so I can go back to the old crush washer. It's a bit of a pain to get that muzzle brake timed without the magic wheel of confusion.

 

[samnev]

I've changed to a flash hider so I can go back to the old crush washer. It's a bit of a pain to get that muzzle brake timed without the magic wheel of confusion.

Even with the magic wheel of misfortune it's really a pita when the shims they call out for whatever position the brake ends up in are out of tolerance and won't time the break. It took 3 calls to Surefire and 2 extra sets of out of spec shims to get a combination that timed the brakes.

 

[Emerson0311]

Resurrecting this necro thread because I’ve got a Howa 300 PRC that I put a no name brake on, and it shoots 1.5MOA+ with Hornady factory 225 ELD-X. I probably over torqued the brake/jam nut, and the factory barrel is super skinny to start with. Initially I blamed the package scope, so now it has a used Razor, but this thread may give me an easy fix. I’ll pull the brake off and try it. It looks like I may get my reloading set up again too. It’s a good day!

 

[ut755ln]

My Search-fu sucks today. If you know where there is an established thread on this, please help me out.

How much (if at all) can the torque of a muzzle brake affect the accuracy of a semi-auto .308? Can the design of the brake also affect this?

Gun: Larue PredatAR 16" 7.62
Brake: Surefire MB762SSAL/RE (the kind that overlaps the barrel a bit)

Thanks in advance for all the help!

The Dead Air break I recently installed said in their directions that over torqueing could impact accuracy, they also said to use the supplied shims to ensure proper timing which also apparently can impact accuracy.