Troy Barrel Nut

Discussion in 'AR-15 Discussion' started by jwhirl413, Dec 12, 2011.

  1. jwhirl413

    jwhirl413 New Member

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    OK, so I have a dpms sweet16 bull barrel rifle. I ordered a troy trx standard rail to put on the upper. When I went to reassemble the upper with the new rail I could not get the barrel nut on. It went easily over the front of the barrel but would not go past the section where the gas block is. I called dpms and troy to get exact measurements to see what is going on. DPMS says that the diameter of the barrel .936 and troy says the inside diameter of the barrel nut is 1.043. What gives? Any help is greatly appreciated. I attached a pic of a dpms barrel(mine isn't fluted) to give you an idea.
     

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  2. FCross7

    FCross7 New Member

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    Use a caliper and measure the two. I doubt the barrel diameter is off, but the nut could of been machine incorrectly. Compare the measurements to what the manufacturer says they should be.

    -Fred
     

  3. Jpyle

    Jpyle New Member

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    Pardon the dumb question but you say "where the gas block is." Have you removed it? The barrel under the gas block may indeed be .930 but the block itself is higher. Does the nut thread on to the upper?
     
  4. jwhirl413

    jwhirl413 New Member

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    Yes the gas block has been removed, it was the first thing off when I removed the free floated tube, gas tube and barrel nut.
     
  5. jwhirl413

    jwhirl413 New Member

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    I measured when I got home today, and the barrel is larger than its supposed to be. It measured 1.045 instead of .936. Took it to a guy I work with and had him shave a little off the inner ring of the barrel nut. Fits like a charm now. Looks and feels better also. Thanks for the help. Pics are before (black)and after(black/tan)
     

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    Last edited: Dec 12, 2011
  6. mjkeat

    mjkeat New Member

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    So the barrel is out of spec? Crazy.
     
  7. jwhirl413

    jwhirl413 New Member

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    To top just my barrel being out of spec, my friend ordered a 20" bull barrel from dpms and its the same size, so we actually had to rework two barrel nuts. 1 more pic
     

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  8. mjkeat

    mjkeat New Member

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    I can't believe a company can do something so many times and still get it wrong. People need to stop purchasing from these companies so they'll go away.
     
  9. jwhirl413

    jwhirl413 New Member

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    I was also kinda shocked by it. I really hate to say that too, b/c soooo many times i've read how dpms is out of spec, and i never really believed any of it, i mean it really shoots well is very accurate and it has been a really nice rifle. I guess the one good thing is that it is a bigger bull barrel than stated, i probably wouldn't be nearly as happy if it was smaller...
     
  10. mjkeat

    mjkeat New Member

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    Is it just a bench rest gun?
     
  11. jwhirl413

    jwhirl413 New Member

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    I actually use it for three gun, the bipod is really just for range trips and pictures(it usually stays in the range bag till needed).
     
  12. cfraga1978

    cfraga1978 New Member

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    Three gun? Then why the bull barrel? Isn't it a little on the heavy side?

    High angle hell. Death and destruction from above.
     
  13. jwhirl413

    jwhirl413 New Member

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    Had the ar before I started 3gun. plus i'm a man and i can carry it :cool:
     
  14. mjkeat

    mjkeat New Member

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    I'd think it would be on the excessively heavy side for 3gun. Man or not that bull barrel is an hindrance.
     
  15. Sniper03

    Sniper03 Supporting Member Supporter

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    I regret to say it, but there has been quite a bit of things from DPMS that has been out of spec lately. I am certainly hoping that moving the plant to Ilion NY will correct some of the issues. But any company can have problems if they are not up on their Quality Control. I have seen three lower parts kits of late that had their rear tail housing of the trigger which was at a 10-15 degree angle off center to one side in the area where the Disconector Spring and Disconector are installed in the trigger? This definitely would have caused a problem and was very obvious upon looking at the trigger. I would not think so much if I had seen one. But I had three students in the past four to five months show me a kit with the exact same problem. So when I read this thread about the barrel. It seems to me that if they are giving a specific dimension on a new barrel .936 and it actually is 1.045 they best be doing a little Quality Control on parts in general. ;)

    03
     
  16. fsted2a

    fsted2a Active Member

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    Sorry to hijack the thread, but my experience with DPMS isn't exactly great. I bought a collapsable buttstock assembly from them, and when I screwed the tube in, I discovered the threads weren't CNC'd. In order to get it to hold the detente down, the tube had to be screwed in enough so that the collapsable stock was at about a 10 degree angle off center. I tried it on multiple lowers, and had the same result. I ended up taking it back to the dealer, and they traded me even for a Bushmaster kit, which had a timing lip on the tube to address that issue.