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Thread: Barrel Nut Torque Question???

  1. #21
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    The TM specifies that the barrel-nut wrench should be inline with the torque wrench. The torque specifications in the TM are specified with the additional length of the lever already compensated for. With that being said, with a 50 lb-ft range for the target value, it's really not terribly critical as long it is tight enough to begin with and something isn't so terribly wrong that there is a risk of damaging the receiver.

    I generally tighten to minimum, set my torque wrench to 80 lbs-ft, and as long as I get lineup without a click, things are good-to-go.
    Last edited by dkindig; 07-29-13 at 14:26.

  2. #22
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    Quote Originally Posted by dkindig View Post
    The TM specifies that the barrel-nut wrench should be inline with the torque wrench. The torque specifications in the TM are specified with the additional length of the lever already compensated for.
    That is what I gathered from the instructions as well. The torque values listed are not at the nut.

  3. #23
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    Modify the barrel nut

    Long story short, I had occasion once to simply file a new slot for the gas tube where the desired toque was indicated. A chainsaw file worked well for this. The gas tube should not bare on any portion of the barrel nut in the first place. The gas tube slots are simply for tool engagement, and loosing two slots at 12 o'clock will not hinder the proper use of most 3-pin wrenches by selecting/engaging three other opposing slots. The hole the gas tube passes through in the upper receiver provides all the alignment necessary.
    ColdBlue sends...
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  4. #24
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    Quote Originally Posted by coldblue View Post
    Long story short, I had occasion once to simply file a new slot for the gas tube where the desired toque was indicated. A chainsaw file worked well for this. The gas tube should not bare on any portion of the barrel nut in the first place. The gas tube slots are simply for tool engagement, and loosing two slots at 12 o'clock will not hinder the proper use of most 3-pin wrenches by selecting/engaging three other opposing slots. The hole the gas tube passes through in the upper receiver provides all the alignment necessary.
    Thats a pretty good idea but what I ended up doing was adding a spikes shim, changing to a different nut and got it to torque at exactly 70 ft/lbs on the money with perfect alignment, took about 5 times of loosening and re-torquing adding 5 ft/lbs but when it clicked at 70 it was exactly centered. This build was a little tricky...

  5. #25
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    Quote Originally Posted by Djstorm100 View Post
    Why set the barrel nut wrench 90 degrees to the tq wrench? If I under stand you correctly. The nut wrench and tq wrench should form a L
    With the wrench offset 90 degrees, indicated torque = actual torque. It has to be 90 degrees though. Anything less (0-89 degrees) will require some math to calculate the difference between indicated and actual torque.

  6. #26
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    Quote Originally Posted by MK18Pilot View Post
    With the wrench offset 90 degrees, indicated torque = actual torque. It has to be 90 degrees though. Anything less (0-89 degrees) will require some math to calculate the difference between indicated and actual torque.
    Actually there is a small sine error introduced with the wrench at 90*. Too small to worry about though...

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