Lower for 6.8 SPC

Discussion in 'AR-15 Discussion' started by mich1377usmc, Sep 29, 2012.

  1. mich1377usmc

    mich1377usmc New Member

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    This is my first trip down this path , building an AR not shooting one. Have read & watched the stickies, VERY well done by ALL. My question is; will ANY mil-spec lower be strong enough for the 6.8 ?? Any maker better than the others are all just about the same ?? This weapon will be used as a range / SHTF / I,m the ODDBALL that shoots 6.8 firearm. Thank You in advance Mickey
     
  2. Sniper03

    Sniper03 Supporting Member Supporter

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    mich,

    Any good lower assembly will be fine for the 6.8 SPC. It is a good round I might add. Certainly a little more expensive unless you reload but is superior to the 5.56. I would suggest the following: Rock River Arms because I love the 2 Stage Trigger and RRA/Hogue grip along with the Star Selector which you can get. Others are Stag Arms, Spikes Tactical, Daniel Defense,Double Star, but any good Lower will do just fine. Let us see some Pics when you get it built.:)

    03
     

  3. nitestalker

    nitestalker New Member

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    What changes are needed to use the 6.8 on a standard Colt preban lower? Can this be done by just changing the upper and magazine?
     
  4. TheAlmightyBob

    TheAlmightyBob New Member

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    Any receiver will work. And other than barrel and mag, you also need a bolt head. The case rim is slightly larger than the standard 223.
     
  5. nitestalker

    nitestalker New Member

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  6. mich1377usmc

    mich1377usmc New Member

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    Thank you for the imput 03. Now I can make an informed purchase from one of the LGS OR NEXT GUN SHOW, them ID 10T will try to sell you the most expensive thing in the case if you let them. Ammo is no prob as I've been reloading for going on 40 years, the first purchase will be hard to swallow but all down hill after that. Have done alot of comparing between 5.56 to 6.8 , it does look like a better round just never fired weapon chambered for ithat caliber. Qualified with M16A1's in the Corps, glad I was an 81mm FO/RTO an carried a 1911A1. Now on to optics , will stay with iron sights at first , but that is another day. Mickey
     
  7. mich1377usmc

    mich1377usmc New Member

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    Been doing research . Have a question for the board , in 6.8 SPC any difference between I or II chambers ie, 6.8 SPC II ? Have from a nice upper kit from M&A. Thank You for the replies. Mickey
     
  8. TheAlmightyBob

    TheAlmightyBob New Member

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    stolen from else where.

    6.8 SPC Chambers Available:

    1: SAAMI / 0.05 " throat / akin to .223 standard
    2: SPC II / 0.10" throat / akin to 5.56 NATO
    3: DMR / 0.08" throat & a 30 degree case to leade taper instead of 45 degrees / akin to .223 Wylde

    Dimensions of the 6.8 SPC
    **************new case––-resized case ––-SAAMI––––––-SPCII––-DMR
    base dia. ******* .4155***** .418**** * .422***** .422 ***** .4205
    shoulder dia. ***** .402 * ** .402 ***** .4028**** * .4028 **** .403
    neck @ shoulder dia* .301 *** .301 **** .3085**** .3085 ***** .305
    neck @ throat dia ** .301 *** .301****** .307 ***** .308 **** .304
    leade dia. ***************** ********* .2781**** .2781 **** .277
    length of leade ******************** ** .064**** .105 ****** .095

    eta: spec1 chambers had problems with hot loads. Starts showing pressure signs early. Just thought you should know.
     
    Last edited: Oct 5, 2012
  9. mich1377usmc

    mich1377usmc New Member

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    Bob Thanx for the reply That was my thinking on difference the between chambers. Going to call retailer today and get more specs. Even if this outfit is just a SAAMI chamber will still purchase because its a good deal. Can always up grade barrel at latter date. Mickey
     
  10. Gatoragn

    Gatoragn Active Member

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    I have a LMT 6.8 carbine upper. I acquired a DPMS (gasp) stripped lower, RRA parts kit w/2 stage trigger. Since I assembled this exclusively for hunting I used a fixed stock. On the upper I cut down the front sight and installed a mid-length free float hand guard.

    It will shoot minute of venison all day. Now I just need a couple of Bambi daddies or mommas to show up this year.
     
  11. treehugger49

    treehugger49 New Member

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    Here's a great place for all things 6.8 SPC, particularly in the discussion of chamber design and the history behind the evolution of the SPC II:

    http://68forums.com/forums/forum.php

    My build involved a Mega upper w/ ARP 18" stainless SPR bbl mated to a Mega Gator lower, with a RRA LPK and Vltor E-mod mil-spec stock kit.

    Couldn't be happier!
     
  12. mich1377usmc

    mich1377usmc New Member

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    Have legal question. Has anyone dealt with M&A Parts, they have good deal on complete 6.8 SPC upper kit , everthing but lower. they tell me that they can ship to my house without going through FFL dealer . I live in NC . I know about the lower & the FFL bit, looking now for one from LGS's Any help, many thanks Mickey
     
  13. TheAlmightyBob

    TheAlmightyBob New Member

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    Anything for an AR can be shipped to your house including anything and everything thats goes in a lower receiver. Except of course for the stripped lower receiver itself. (Any and all class 3 excluded)
     
  14. mich1377usmc

    mich1377usmc New Member

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    Picked this up Sat. Tactical Innovations w/STBA

    ForumRunner_20121008_040206.jpg
     
  15. AgentTikki

    AgentTikki New Member

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    Nice lower, I've built a few TI 80% lowers myself. Good stuff.

    If you reload, have you looked into 6.5 grendel and 300 blackout?
     
  16. mich1377usmc

    mich1377usmc New Member

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    I looked but this be my weapon, may build a 300 BO for the wife in a few months . Her choice she wants to shoot this 6.8 first & yes I reload that is why a 6.8 build. Everything should be here in the next few days. Christmas came early this year. LOL. Mickey
     
  17. mich1377usmc

    mich1377usmc New Member

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    This came on Wednesday,ain't slept well since, is this early onset of BRD. LOL. Will put this together today after I come back from gun show in Big Lick. NC . Mickey

    ForumRunner_20121012_063210.jpg
     
  18. AgentTikki

    AgentTikki New Member

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    Losing sleep? Um yeah....its getting bad...

    Next phase is when you start planning out paychecks....
     
  19. mich1377usmc

    mich1377usmc New Member

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    She is put together. Now have a rash & discharge, smells like Hoppe's #9 guess I'm terminal. LOL. Now on to iron sights , mags , ammo , optics later. Mickey

    ForumRunner_20121013_082401.jpg
     
  20. TheAlmightyBob

    TheAlmightyBob New Member

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    Hate to tell ya this. But you built it up side down....... i have found the magpul rear flip up sight to well worth the money. Easy to function and really a great price to get you running.