Muzzle brake affecting accuracy?

Discussion in 'AR Pattern Rifles' started by Sas quatch, Jun 29, 2020.

  1. Sas quatch

    Sas quatch Active Member Supporting Member

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    I've got a Colt AR that I used to use for 3-gun. I had an el-cheapo, and stupid-loud brake on it and it shot great. But then then accuracy started going downhill. I took a look at El-Cheapo, and found that it was starting to wear, where the bullet passed was out of round.

    So, I decided to go quality- I bought a VG6 epsilon, and accuracy has not improved. I've tried commercial ammo, handloads (that shoot great in other ARs) and can't get better than ~3MOA when it used to shoot closer to 1.

    Looking at the design, I see that the hole near the threads is close to round (.223) size, then it goes into an expansion chamber- and then it necks down again to near .223 size. Doing some reading, and comparing it to other brakes, that's unusual. Usually the second bore is quite a bit larger- closer to what flash hiders do. Or not- a lot of these have a small exit hole

    Can a muzzle brake have that big a difference in accuracy? I know it can change POI because of harmonics, but this is simply worse accuracy.

    I'm going to test it with a simple YHM flash hider to see if accuracy improves.

    The other possibility is that I've shot out the barrel, but it has <2000 rounds through it so that seems low for it to shoot that poorly.
     
    Last edited: Jun 29, 2020
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  2. bashman

    bashman Happy to be here

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    What is your sighting system on this rifle? If optics, have you verified the mount and/or rings are still tight and haven’t worked loose?


    Sent from my iPhone using Tapatalk
     
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  3. USMC6094

    USMC6094 Schnitzengruben

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    The KISS principle applies here, did you notice copper/brass transfer at the 12 o'clock or any other place on the brake?

    You noted that the exit hole was worn out of round, that indicates bullet contact with the brake, which equals NOT good for accuracy.

    If that's the case, your brake is the problem
     
  4. NKD

    NKD Senior Member Benefactor Kimberless Supporting Member

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    Seems like flame/gas cutting could wear a round hole oblong, no?

    Brake could be off a hair. If brake/ barrel/ thread concentricity isn’t dead nuts it seems like it could certainly cause accuracy issues.
    Could be a tolerance stacking issue.

    I’m no expert, just throwing out ideas.
     
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  5. Slacker

    Slacker Liquor and Whores...

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    Try it with no brake and see if it groups.
    Or just an A2 birdcage.
     
    Last edited: Jul 1, 2020
  6. Sas quatch

    Sas quatch Active Member Supporting Member

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    Thanks for the replies- yes, I've got a simple flash hider mounted now (YHM), but need to test it for groups.

    Regarding the old brake, it was out of round where it meets the barrel, not the exit. I think it was like @NKD said, just flame cutting. In fact, that's what it looked like, burnt metal. Like I said, it was cheap, and used to be accurate.
     
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  7. JBoyette

    JBoyette Well-Known Member

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    Yes,

    I designed the WORLDS GREATEST flash hider and took a known 1 MOA .223 and installed my ULTRA DESIGN!!!!

    first 5 shot group at 100yds was 6 MOA. Took of the break on the range back to 1 MOA. Played with different brands of crush washers and I went from 5 MOA to 6 MOA to 7 MOA groupings.

    After 6 weeks of adjusting this, doing that, I got it to 3 MOA.

    so it happens.

    Lastly,

    you could have a warn crown on the barrel due to the use. Check that first if I was you.
     
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  8. Sas quatch

    Sas quatch Active Member Supporting Member

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    Ok, testing today: good news, it wasn't the muzzle brake. Bad news: no clue. Someone above suggested the optic might be loose- or bad. I'm going to swap it out and test again.
     
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  9. YeeHaa

    YeeHaa Member Charter Life Member

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    As you know, there are several variables involved with obtaining good / acceptable accuracy.

    To help answer your question regarding muzzle devices / muzzle brakes having a big difference in accuracy, ,, absolutely yes.

    What the guy in the video below is doing is what I've done with any rifle I own that will accept a muzzle device.

    Anyone that's skeptical that harmonics will not change things that much, just start at TS 28:54 and check out the "Limbsaver" section.


     
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  10. YeeHaa

    YeeHaa Member Charter Life Member

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    Here's his results for a 6.5 Grendel AR-15

    Grendel AR15 muzzle devices.png



     
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