300 rum

Discussion in 'Gunsmithing' started by ig25, Jan 27, 2014.

  1. ig25

    ig25 Well-Known Member

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    I have a go gauge for my 300 rum and was wondering if anybody compared their go gauge with the case specs?
    Mine seem to be longer the base cartridge specs. Can anybody caliper theirs and tell me their specs?
    Thanks
     
  2. J E Custom

    J E Custom Well-Known Member

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    The go gauge is longer than loaded cartridges so all of the ammo will fit the chamber.

    Most manufactures size there ammo smaller than the SAAME chamber spec, Some even use small base dies for there ammo.

    When setting up head space for a person that does not reload I use the go gauge with .001 to .002 shims
    max over the go gauge.

    If a person loads all of his/her ammo them I will set the chamber a .0000 with the go gauge so they feel slight bolt contact with the cartridge for better accuracy with factory ammo. and once they are fired the dies can be set to minimize working the brass to much.

    With belted cases .001 to .0025 is needed to assure the rounds will chamber. Once fired you can size them as shouldered cases and improve accuracy.

    J E CUSTOM
     

  3. ig25

    ig25 Well-Known Member

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    I do reload all. I originally set the head space the go gauge. With the bolt closing snuggly. Which is or was a very tight chamber. Not letting me get close to max powder charge of H1000 with out getting a stuck cartage. So I set it up now with a go gauge and 1 piece so tape .002. The hope was to eliminate this. Once fired brass I am going to neck size only
     
  4. J E Custom

    J E Custom Well-Known Member

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    That will work.

    I size the chamber between the go gage and a factory ammo to keep from stretching the brass in the first firing And size it to just chamber with a little resistance. If you are seating close to the lands that may contribute to the stuck cases.

    Do what ever it takes to prevent a stuck case.

    J E CUSTOM
     
  5. den

    den Well-Known Member

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    does adding the headspace ever mess with accuracy for you guys, or does it stay about the same?
     
  6. J E Custom

    J E Custom Well-Known Member

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    Once it is fire formed to your chamber it has no head space unless you size it that way.

    .001 or .002 thousandths wont effect accuracy that much normally. for better brass life I advise
    that you should size no more than necessary to chamber.

    J E CUSTOM
     
  7. den

    den Well-Known Member

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    and it possibly will still stop the cases from sticking at low charges because there will be .002 tho more room in the chamber to let the cases spring back down right ?