7.62x39 vs 7.62x35 (300 Blackout) Comparison

Discussion in 'The Ammo & Reloading Forum' started by tuckerd1, Dec 6, 2017.

  1. tuckerd1

    tuckerd1 Moderator Supporting Member

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    Why a 300 Blackout while 7.62x39 existed? Just because they could?

    762x39vs300 Blackout.jpg
     
  2. southernshooter

    southernshooter Well-Known Member

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    Suppressors have fueled the 300 craze. So has States allowing suppressors use while hunting. I don’t reload but my understanding as well, is subsonic 300 can function almost flawlessly in semi auto AR platforms both suppressed or not. I’ve been told it outperforms 5.56/223 in short sub 10” barrel AR pistols and SBR’s as well


    With all that said I’ve never jumped on the 300 bandwagon. 5.56 and 9mm is the only calibers I’ve ever needed in AR’s
     

  3. Kvasir

    Kvasir Active Member

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    I built up a 300 Blackout a few years ago and absolutely love it. Mostly because I do reload.
    There is a tremendous variety of bullets available as it uses a standard .308 diameter. It fact one of my favorites is a 155 grain cast and gas checked 7.62x39 that I size down to .309.
    This shoots sub MOA with ease. The disclaimer being that this is a custom hand made gun, using custom hand made ammo that is sized to that particular gun. Actual mileage may vary.
    Other than that, the advantage is all components of the gun are shared with the 223/5.56 excepting the barrel. So they are cheaper to build than a 7.62x39. Even the brass that I use is cut down from 223/5.56 cases.
    Ballistics are roughly the same between the two cartridges. I believe that was the original intention.
    The sub-sonic 230 grain loads I made up fire and eject fine without a suppressor, but do not drive the bolt back far enough to cycle the next round. This may be corrected with a lighter BCG. But as suppressors are not legal in Illinois, I just don't shoot those much.
     
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  4. soundguy

    soundguy Well-Known Member Supporting Member

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    Yup, same mag and bcg as 556.

    X39 AR mags are odd
     
  5. mogunner

    mogunner Well-Known Member

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    Straight case on the .300 versus the tapered case on the x39 makes the difference plus the ability to cut down your .223 brass to make the .300. Only a couple companies make mags for the x39 while ten zillion make .223/5.56/.300BO mags
     
  6. tuckerd1

    tuckerd1 Moderator Supporting Member

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    I built an AR for 7.62x39. I assembled the lower and bought a complete upper. It is the least expensive AR I have built. I use Stoner mags and they feed well. Ammo is plentiful and cheap. It is a plinker so not expecting sub MOA
     
  7. soundguy

    soundguy Well-Known Member Supporting Member

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    Stoner at 556 mage?
     
  8. tuckerd1

    tuckerd1 Moderator Supporting Member

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    Stoner 7.62x39 mags. Looks like an AK mag
     
  9. soundguy

    soundguy Well-Known Member Supporting Member

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    Ahh, those. Those look like what promag used as a template.

    I have several colt and promags, so far, so good.
     
  10. soundguy

    soundguy Well-Known Member Supporting Member

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    Its just sad that smartphones must change "AR" to " at" and "mags" to "mage" with spell correct....
     
  11. mogunner

    mogunner Well-Known Member

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    Stoner mags are actually manufactured by ASC or CPD. I've had no problems with the 10 and 20 round ASC mags that I run, but they are of new manufacture, I know pretty much everyone had problems with their early designs.
     
  12. Pawpaw40

    Pawpaw40 Well-Known Member

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    The tapered case of the 7.62x39 round often caused problems associated with excessive bolt thrust in the AR platform. My understanding is that has been resolved in the newer bolts made for the Russian designed round. The reason for the cartridge is commonality of parts and, similar ballistics to the X39 with lightweight bullets, and the ability to go subsonic with heavy bullets that are easily accessible.
     
  13. soundguy

    soundguy Well-Known Member Supporting Member

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