Need help with thread sizes for muzzle brakes

Discussion in 'Gunsmithing' started by Beelzebub, Aug 31, 2013.

  1. Beelzebub

    Beelzebub Well-Known Member

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    171
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    Dec 26, 2010
    I've got three rifles I am seriously thinking about putting brakes on. If I list the caliber and outside diameter of the barrel can someone tell me the largest (OD) and smallest (AND STILL SAFE) thread acceptable.


    6MM OD = .810

    6MM OD = .540

    277 OD = .660


    thanks in advance for any assistance,
    Beelz
     
  2. orwapitihunter

    orwapitihunter Well-Known Member

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    Jan 4, 2004
    6mm (.810")
    1/2x28 tpi (small)
    9/16x24 tpi (medium)
    5/8x24 tpi (large) <--My choice

    6mm (.540")
    These are the ones I hate. For me, there just isn't a warm and fuzzy feeling on this one.
    (1/2") = Not as much shoulder, as i would like, for the brake to seat against. And if the bore isn't centered in the barrel it makes it even worse.
    (7/16") = Not a commonly offered muzzlebrake thread diameter. Also getting kinda thin between the bore and the threads.
    If forced to put a brake on this one I would look for a very fine thread in 7/16", or make my own.

    .277 (.660")
    1/2x28 tpi getting a little on the small side.
    9/16x24 tpi <--My choice
    5/8x24 tpi getting too big for a good shoulder for the brake to seat against.

    The TPI's that I listed are just a common choice. If the brake you want is offered in 32 tpi instead of 28, it will work fine.
     

  3. Beelzebub

    Beelzebub Well-Known Member

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    171
    Joined:
    Dec 26, 2010
    XXXXXXXXXXXXXXXXXX

    Thanks much for the info. I was a little worried about the Model 7 243 also. I'm braking it for my grandson.

    Appreciate you,
    Beelzebub