AR15 build, any advice?

Discussion in 'AR-15 Discussion' started by rembrant88, Apr 2, 2012.

  1. rembrant88

    rembrant88 New Member

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    I'm new to the semi auto build and this year I want to build a few ar's, if you guys would stop buying all the parts :rolleyes:. For the first one I have a complete CMMG lower, and a DPMS stainless upper without the internals. Now, some people tell me you can just slap the upper to the lower and you are good to go while others tell me I need to take it to a gun smith and have it head spaced (?). I have a carrier assembly that came out of an Armilite ar that I was going to use.

    I'll do some searching on this site, but until then I was hoping you guys could educate me on the complete build concept and explain some of the do's and don'ts involved in these builds.

    Thanks.
     
  2. Gatoragn

    Gatoragn Active Member

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    Probably a good investment to have the head spacing checked on the upper.

    Head spacing makes sure the round is properly seated in the chamber once the bolt locks into place.

    If you purchase a complete upper you are usually good to go.

    Yes you can mix & match mil-spec AR15 lowers & uppers. Some (maybe all) Colts have some funky pivot/takedown pin sizes.
     
    Last edited: Apr 2, 2012

  3. BenLuby

    BenLuby New Member

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    Without the internals means no BCG or charging handle, right? If that's the case, then you should only need to order those two parts, then pin them together and be good to go.
     
  4. rembrant88

    rembrant88 New Member

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    Alright, thanks. I just can't seem to wrap my mind around the idea of how a gun like this would be head spaced. But I guess that's for the gunsmith to worry about. I'll call a guy today.

    Yeah, I don't have the charging handle, just the armilite BCG. So the charging handle is the only part I need to buy. I heard there is a charging handle that is better for scoped ar's, do those cost much more?
     
  5. AgentTikki

    AgentTikki New Member

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    You can get a standard charging handle for about $20. Some people opt for a larger latch to help clear their optics. I like the BCM Vltor Gunfighter MOD 3 (large latch).
     
  6. Quentin

    Quentin New Member

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    ArmaLite bolts have a relieved lug opposite the extractor but it should work. I'm hesitant to recommend it since from here it sounds like you're slapping together used parts and have a DPMS upper. A lot of us like to use the same mfg for bolt and barrel to increase the chances for proper headspace. And don't like to throw in a used bolt from another gun into a used upper. Yeah, be safe - have the headspace checked.
     
  7. AgentTikki

    AgentTikki New Member

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    I also remember reading reports of factory fresh DPMS chambers being out of spec and not liking 5.56 ammo.............. +1 headspacing check.
     
  8. rembrant88

    rembrant88 New Member

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    $25 to have the head space checked. Not bad. I might get that charging handle. I'll look it up and see what the price is.

    I'm tempted to get a different bolt then, if it is a smarter move. I just thought since I had one lying around I'd use it but maybe it's not a good idea to mix and match so much.
     
  9. Quentin

    Quentin New Member

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    Well the ArmaLite bolt is tough so if it doesn't have a lot of hard use it might be ok, again it's worth the cost to check headspace on what you already have.
     
  10. rembrant88

    rembrant88 New Member

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    The bolt looks new and that is what the guy told me when I bought it. He threw it in with some ammo I bought a few years ago.

    Hey, just noticed where you are from. I live in Boise also. What do you think about Ed Sweet as a gunsmith? I've had him do other jobs for me so figured I'd have him check this ar out.
     
  11. JSDenson07

    JSDenson07 New Member

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    Easy check if you reload and youre worried about head space 1)seat a bullet in brass 2)insert into chamber 3)allow the bolt to come home GENTLY 4)press your forward assist 5)rack bolt to the rear catching the bullet. 6)Measure. Instant head space gauge. Also seat the bullet .02 deeper when reloading to tune your loads to your firearms chamber. Just remember to give me some credit when you repost this on another thread!
     
  12. rembrant88

    rembrant88 New Member

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    Good advice. I do reload but my brother needed a place to stay so he sleeps and stores his stuff in my reloading room. Makes it difficult to do much in there but I'll try what you said.

    I'll pass on the word and take the credit for myself :p. No, I got your back. Thanks for the tip.
     
  13. JSDenson07

    JSDenson07 New Member

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    Haha no prob man hopefully ill see your rifle on a thread soon!