Loose barrel extension?

Discussion in 'Rifle Country' started by M1key, Feb 5, 2014.

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  1. M1key

    M1key Member

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    Anyone ever gotten a barrel with a loose extension? This was ordered from Primary Arms, arrived today. Made by DSA. I noticed the extension was finger tight and screwed right off...not good.

    Also it had no cuts for front sight pins. Is no one doing this anymore?

    M
     

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    Last edited: Feb 5, 2014
  2. DougW

    DougW Member

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    Send it back. I would not use it. The extension is supposed to be torqued on to the barrel.
     
  3. M1key

    M1key Member

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    Primary Arms has already been notified. Funny, they had no idea what I was talking about and asked me to send pictures...LOL

    Oh well, it's definitely going back.

    M
     
  4. Strahley

    Strahley Member

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    Is it just me, or do the threads look rusted?
     
  5. MrCleanOK

    MrCleanOK Member

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    Nevermind that the pin in the barrel extension is supposed to engage a blind hole in the barrel. That thing is all kinds of wrong.
     
  6. M1key

    M1key Member

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    They're rusted
     
  7. rcmodel

    rcmodel Member in memoriam

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    That right there just ain't right.

    On more then one level!

    rc
     
  8. 1911 guy

    1911 guy Member

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    Um, yeah. Not good. First the rust issue, then the complete lack of proper torque.

    I can't help but think that every barrel and extension from them is suspect. Why was the extension not torqued immediately upon mating with a barrel? How many more are out there that got shipped like this?
     
  9. rcmodel

    rcmodel Member in memoriam

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    I'd have too guess that during the recent crunch?

    Some minimum wage guy in the back warehouse was task with screwing extensions on barrels for later final cleaning, torquing, & headspace check by a higher paid employee in the heated part of the shop.

    They just got put on the rack & shipped before final cleaning & assembly.

    Rc
     
  10. sansone

    sansone Member

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    this^^
     
  11. hentown

    hentown Member

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    If the indexing pin engages a blind hole in the barrel, then how is headspace set? I've bought and installed a bunch of AR barrels. Never bought one that had cuts for the sight base pins.
     
  12. M1key

    M1key Member

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    You can buy new barrels with a pre-installed, pinned front sight. I'll have to go that route. I didn't want to have to buy more parts. I've tried to have stripped barrels cut with very limited (no) success. I just wish manufacturers would include the cuts...


    M
     
    Last edited: Feb 6, 2014
  13. briansmithwins

    briansmithwins Member

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    Headspace is set after the barrel extension is installed. That way the chamber is cut for the current extension, which had some variable dimension.

    After the extension is installed the gas port is drilled, since the index pin sets TDC. After all that is done the FSB would be installed and the taper pin holes drilled thru the FSB and barrel all at once.

    BSW
     
  14. Howard Roark

    Howard Roark Member

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    The rust is from Parkerizing solution seeping in under the extension when it was parked. They should be done separately to avoid this.

    The pin isn't seated properly because of all the metal that was removed behind the threads. I undercut mine some to assure a flat surface for the nut to jam to but not that much.

    There is no need to headspace with the extension on the barrel if one has and can read a micrometer.
     
  15. MrCleanOK

    MrCleanOK Member

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    M1key, there is no such thing as a barrel that comes already drilled for you to select and pin your own gas block later. The gas block is aligned on the barrel, then the two are drilled together to keep the parts in alignment. If you tried to drill the barrel and gas block at different times the holes would never line up and you'd never get them pinned. Once a gas block is drilled for a specific barrel, they are buddies for life and can't be swapped for other pinned components (you can swap pinned for set screw gas blocks, etc)
     
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