AR10 buffer tube

Discussion in 'AR-15 Discussion' started by dickpalmer, Feb 16, 2012.

  1. dickpalmer

    dickpalmer New Member

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    So, I can't find an AR-10 section. I have a question anyway. I have a DPMS LR-308. It currently has a Magpul PRS stock. I want to switch it to a mil-spec adjustable stock. I can't find a 308 mil-spec tube on DPMS's web page, only commercial. I talked to Mark there and he said to buy the parts individually if I want Mil-Spec. The threading on AR15 buffer tubes is standardized, so are the AR10's also? Any suggestions on a tube, spring, buffer combo to work with a collapsible stock? Can I use my existing spring and buffer?
     
  2. Jpyle

    Jpyle New Member

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    Not a whole lot of standard AR 10 parts unfortunately. I would search for parts that specifically guarantee they will fit an LR 308 receiver, this way you can at least return it if needed. Try RRA, they sell a lot of AR10 parts, many of which are proprietary but their stock may adhere to the DPMS pattern. Joebobsoutfitters.com also list AR10 accessories.
     

  3. Quentin

    Quentin New Member

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    I don't know if the DPMS .308 threading is the same diameter as their AR-15 or ArmaLite's AR-10. You should call DPMS again and get that info.

    ArmaLite's AR-10 does have a milspec tube so standard stocks should fit it fine. So if it will screw in your lower or an AR-15 tube will you should be good to go. Sorry, I don't know that for sure about the threads.

    http://www.armalite.com/ItemForm.aspx?item=10207025
     
  4. dickpalmer

    dickpalmer New Member

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    When I get the buffer tube, will I need a different buffer spring and buffer going from A2 to adjustable?
     
  5. Quentin

    Quentin New Member

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  6. dickpalmer

    dickpalmer New Member

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  7. fsted2a

    fsted2a Active Member

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    For the 308 AR, there are 2 general configurations: Armalite and DPMS. Although some parts are interchangeable, and I don't know which ones, and my questions to the companies have been that they only guarantee THEIR parts will fit on THEIR guns. There may be a few smaller companies that have their own proprietary guns, but most will interchange with either Armalite or DPMS: good luck figuring out which. Hope this helps, and not add to the confusion.
     
  8. Quentin

    Quentin New Member

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    Off the top of my head I'd guess that DPMS and AR-10 tubes would interchange and you'd think they'd be the same thread size as the AR-15. Dumb not to be but of course find out for sure, we see dumb things all the time.
     
  9. mjkeat

    mjkeat New Member

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    The threads and diameter of the portion that is threaded is the same. Before the release of VLTORs A5 guys used their .308 receiver extension on AR15s to get an A2 like buffer system with the ability to still have a collapsible stock.
     
  10. fsted2a

    fsted2a Active Member

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    Q, I agree. You would think that they would all be interchangeable at least with other 308's, but I guess since there isn't as big a market as for the AR15's, there is no push for standardization. I do know that DPMS and Armalite 308 mags will NOT fit in each others rifles, and their uppers and lowers can't be swapped. I have been told that BM will fit DPMS, but what else goes to what is anybody's guess.
     
  11. fsted2a

    fsted2a Active Member

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    Good info. I STILL don't recommend DPMS collapsable stocks, for the reasons I have stated in past threads. Ok, I know I keep kicking a dead horse. :eek:
     
  12. Quentin

    Quentin New Member

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    Thanks, MJ, good info as fsted2a said. Way back in the 1950s you'd think ArmaLite would have used the same receiver extension threads for the AR-10 and AR-15 (no reason not to since the AR-10 was first and the same tube could be used in the scaled down AR-15). And why not carry forward to the new ArmaLite company AR-10B, DPMS, BM and RRA but you never know until someone tries it.
     
  13. Quentin

    Quentin New Member

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    Fsted2a, no argument here! :D
     
  14. MisserMartin

    MisserMartin New Member

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    Just to clear up (or add to) the confusion. There are three variations of collapsible buffer tubes used on the more popular 308 AR's. The main difference being the depth of the hole drilled inside the tube. I don't have the exact specs off the top of my head so bear with me.

    DPMS LR308 (and probably others) uses a tube with a 7" deep hole. They require a shorter buffer than the Armalite or RRA models. This tube is also the one used on standard AR15's.

    Armalite AR10 uses a tube with a 7 3/4" deep hole. They use a buffer that is roughly the same length as the standard AR15 buffer but the 308 buffer is heavier - approximately the same weight as the H3 buffer.

    RRA (and probably the discontinued Bushmaster) use a tube that is drilled (I believe) a little over 8" deep. I belive they also use a standard length carbine buffer but I'm not sure of the weight.

    Hope that helps.