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M1 Carbine Gas Pin

Discussion in 'Rifle Country' started by dscottw88, Nov 7, 2007.

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  1. dscottw88

    dscottw88 Member

    Aug 2, 2007
    Went and shot my M1 carbine today, the rifle jammed and so I took the stock screw off the end of the receiver and discovered that the the pin that the the gas presses rearward, and in turn pushes the op-rod rearward, had come off from under the barrel. So both the pin, and the round hollow screw are now off.

    Do I just screw it back in? and if so, do I do it so that the large part of the pin is closest to the muzzle? And, how far do I screw it in? I can only get it to make a complete revolution once before it gets stuck.

    Any advice would be greatly appreciated. Thanks!
  2. dfariswheel

    dfariswheel Member

    Dec 26, 2002
    It's possible the threads in the gas cylinder have been damaged by the loose nut, or the threads may be coated with carbon.

    If the threads are further damaged by trying to insert a nut in already damaged threads, this will ruin the barrel.

    I strongly suggest taking the rifle to a good gunsmith.
    There is a special tap that can be used to refresh the damaged threads in the gas cylinder, and restore the rifle to use.

    The small gas piston, the "pin" goes into the gas cylinder LARGE end first.
    Then the hollow castle nut is threaded in ALL THE WAY, until it can be tightened down tight.
    In the military, they staked the nut in place to prevent just what's happened to you: The nut unscrewing.

    Again, if you attempt to just reinstall the nut by forcing it to screw in, it's likely the barrel will be ruined.

    In any event, don't re-use the old gas piston or nut. Buy new USGI parts to replace the old ones. Often they are worn or damaged.
  3. Gifted

    Gifted Member

    Jul 28, 2004
    LUcky. Probably similar to what happened to mine, but the gas block cracked and I had to send it back to AO(it was a new manufacture replica) for repairs.

    Second on the smith. Someday I'll know enough to fix it myself, but until then...
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