Correct Measuring Point For Shotgun Barrel

Discussion in 'Maintenance & Gunsmithing' started by RVTECH, Aug 19, 2010.

  1. RVTECH

    RVTECH
    LaPine
    Well-Known Member

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    I am sure this has been covered before but I am about to shorten the barrel on an older Mossberg 500 and I would like to know where the "official" starting point is to correctly measure the barrel to keep it legal. Thanks!
     
  2. swoop

    swoop
    Milwaukie, Oregon
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    Just include the chamber when you measure and you have it. Make sure to keep it 18" or over though.
     
  3. PhysicsGuy

    PhysicsGuy
    Corvallis, OR
    Resident Science Nut

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    Install the barrel on the gun, close the action, and put a wooden dowel down there barrel against the bolt face and measure to the end of the barrel. This is the correct method of measuring length.
     
  4. swoop

    swoop
    Milwaukie, Oregon
    Well-Known Member

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    Hey that will work too, but the cops just hook a tape on the end of the barrel and measure to the end of the chamber. All my barrels measure the same inside or outside and bolt face are flush with the chamber when action is closed.
     
  5. PhysicsGuy

    PhysicsGuy
    Corvallis, OR
    Resident Science Nut

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    The only flaw with that method is that it doesn't work too well if you don't know exactly where the chamber starts, such as when the barrel has extensions that go into the receiver, or if the barrel cannot be easily removed.
     
  6. swoop

    swoop
    Milwaukie, Oregon
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    I see your point on that, but I don't think that would be a factor on his old 500. To be on the safe side with all shotguns, I believe your method would be better. Swoop'
     
  7. huntpotter

    huntpotter
    SW WA
    NRA Life, Clark Rifles, Small Game Hunter Bronze Supporter

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    Looks like there is your exact answer. I'ld cut it to 18-1/2" to be on the safe side, and to allow you to recrown it later if you need to.
     
  8. oregonshooter

    oregonshooter
    AMERICA
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    +1 and because most after market tubes are for 18-1/2 because manufacturers cut to that length.

    Might be interested in this also...
    tutorial_shortening_a_shotgun_barrel_with_hand_tools
     

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