Olympic AR barrels on clearance

Discussion in 'Hot Deals' started by John A., Apr 16, 2017.

  1. John A.

    John A. I'm "THAT" guy Staff Member Global Moderator Forum Moderator

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    16" M4 barrels: $114.95 blackened 416 stainless steel
    16" HMG barrels: 104.95 4140 Chromemoly steel Heavy Machine Gun (HMG) Contour barrels

    http://www.olyarms.com/shop/closeouts.html

    If I were in the market for a good, accurate barrel, I'd jump all over the M4 stainless barrel. I had one back in '04 and it was the most accurate 16 inch AR barrel I ever owned.
    Rossignol likes this.
  2. SHOOTER13

    SHOOTER13 ON DUTY Staff Member Global Moderator Forum Moderator

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    Yup...got the email too !!

    Thanks John...
  3. CaddmannQ

    CaddmannQ .308 Supporter

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    How easy is it to headspace these guns when you change the barrel?

    I thought about picking up that bull barrel for the new AR build, but I was really planning just to get a complete upper custom built.
  4. John A.

    John A. I'm "THAT" guy Staff Member Global Moderator Forum Moderator

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    You don't have to headspace an AR.

    I know that sounds stupid, but if you give me a second, I'll explain why.

    The barrel extension is pinned onto the barrel. It is mechanically fixed at the factory.

    The barrel slides in the receiver and there is a little groove in the upper receiver notched so the barrel extension pin will fit in it. This does 2 things.

    1. Ensure the barrel won't twist/rotate as you're tightening up the barrel nut/handguard
    2. The barrel extension, if pinned correctly, ensures that the gun will be within proper headspace.

    *There may would be a time when you're using an old (worn out) bolt where the headspace may be excessive and unsafe, but I have never seen a new(ish) bolt and barrel ever not pass headspace gauging.

    You can't really change headspace in an AR15 unless you replace the barrel/barrel extension and/or the bolt.
    SHOOTER13 and CaddmannQ like this.
  5. CaddmannQ

    CaddmannQ .308 Supporter

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    John if I could ask you one more question, whats the factory tolerance on the AR-15 headspace?

    I imagine that being an automatic design it would allow for considerably more than a bolt gun.

    But I'm just imagining here....
  6. John A.

    John A. I'm "THAT" guy Staff Member Global Moderator Forum Moderator

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    556 max
    http://www.brownells.com/gunsmith-t.../5-56mm-maximum-headspace-gauge-prod6646.aspx

    223 field gauge
    http://www.brownells.com/gunsmith-t...dspace-gauges/headspace-gauges-prod19183.aspx

    Ideally, it will close on a go gauge, and not close on a no go gauge, but if it closes on a nogo gauge could still be within acceptable (just worn) headspace. If it closes on a field gauge, that's pretty much the end of the barrel life.
    SHOOTER13 likes this.
  7. CaddmannQ

    CaddmannQ .308 Supporter

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    Hah! This was a case of rookie-itis.

    Here I was thinking I'd need to cast the chamber or such.

    I should have known it would be much easier to set things up.

    They've only been making these things (gauges) since the industrial revolution.

    My books all give the proper dims, but tolerances aren't shown. They will evidently be described in the SAAMI docs.
  8. John A.

    John A. I'm "THAT" guy Staff Member Global Moderator Forum Moderator

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    Nothing wrong with asking a question. Hopefully the answer was pretty straight-forward.

    In all fairness, there are several different AR15 chamber sizes to be honest. And not all suited for every bullet out there. The 223 wyldde seems to be the most versatile overall, followed by the 556 nato, which both accept the longer bullets. Also, the oldest 223 rem isn't supposed to shoot 556 through it. So, perhaps your question should be which 223 chamber do I need to buy?

    223 wyldde
    223 rem
    5.56x45 nato

    I still am partial to 1:8 twist wylde in stainless or nitride myself.
    SHOOTER13 likes this.
  9. CaddmannQ

    CaddmannQ .308 Supporter

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    There is more than one way to answer a question . . . even for non-politicians. ;)

    You knew what I needed, and you covered what I really needed to know.

    I'm just trying (unsuccessfully) to remain unembarassed by my own ignorance. LOL
  10. John A.

    John A. I'm "THAT" guy Staff Member Global Moderator Forum Moderator

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    This isn't one of those forums where anyone belittles others for asking an honest question.

    Nobody knows everything.

    When I have a question, I'm comfortable asking here. You should be too.
    SHOOTER13 likes this.

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