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Please School Me!!

Discussion in 'Rifle Discussion' started by Izzy, Nov 26, 2010.

  1. Izzy

    Izzy Oakridge Active Member

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    I have read a lot of threads on older military rifles & have come across the term "counter bore" quite often

    Please
    make this term clear for me!!

    Thanks!:D
     
  2. spengo

    spengo GLORIOUS CASCADIA Active Member

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    If an old surplus rifle has a barrel that is completely shot-out to almost smoothbore at the muzzle, re-crowning will not help. So what they do is they cut new rifling in the opposite direction and crown it inside the barrel. If done correctly it should be a very accurate shooter. Left is counter-bored.
    k169150counterbore.jpg

    k169150counterbore.jpg
     
  3. Izzy

    Izzy Oakridge Active Member

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    Will it always be as apparent as your photo?
     
  4. spengo

    spengo GLORIOUS CASCADIA Active Member

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    "Apparent" you mean? Yes. :thumbup:

    Don't take it as something wrong with the rifle if you see one counter-bored though. It could be the most accurate one in the barrel. Just make sure that the new rifling is sharp and nice looking like you would in any gun. :)
     
  5. Izzy

    Izzy Oakridge Active Member

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    "CRAP" :bluelaugh::laugh:
     
  6. trainsktg

    trainsktg Portland OR Well-Known Member

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    Some counterbores go deeper down the rifle than others. Another easy way to tell if it is counterbored is to take a cartridge and stick it bullet first into the muzzle. If the barrel swallows the bullet to the case rim, its counterbored.

    Counterbored rifles can be very accurate.

    Keith
     
  7. madcratebuilder

    madcratebuilder Ardenwald, OR Well-Known Member

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    I have never heard of this before, really cut new rifling in the opposite direction. That would only work if you went to a larger caliber.

    Counter-boring is done to remove damaged rifling near the crown of the bore. Normally this rifling has been damaged by years of poor cleaning practices(mil-surps). The muzzle end of the rifling is critical to accuracy. Counter-bore = the muzzle-end of the barrel is bored out by using a piloted reamer to remove damaged rifling.

    k169150counterbore.jpg
     
  8. Dyjital

    Dyjital Albany, Ore Flavorite Member Bronze Supporter

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    90* at end of muzzle so bullet leaves the barrel straight?
     
  9. ogre

    ogre Vancouver, WA Well-Known Member

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    What madcratebuilder said. +1