GUN So, lemme get this 5.56 / .223 straight

Discussion in 'On Topic' started by cjj92yj, Feb 15, 2008.

  1. cjj92yj

    cjj92yj Guest

    You can shoot either through a 5.56 upper, but you can only shoot .223 through a .223 upper?

    If this is correct, what's the main reasoning behind it. Looking at that Prvi Partisan 1000/$330.01 in the other thread and it was listed as both 5.56 and .223.

    What gives.
     
  2. sneakyjesus

    sneakyjesus New Member

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    looks right to me... there are case dimension differences and pressure differences...

    stand by for more info than you ever wanted to know about 5.56/223

    http://ammo.ar15.com/

    read on, brother!
     
  3. thedude11

    thedude11 New Member

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    A Wylde Chamber allows both to be fired, correct?


    Edit: Answering my own question -
     
  4. Soybomb

    Soybomb New Member

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    The ammo oracle appears broken but the relevant info is still there
    http://www.ammo-oracle.com/body.htm
    Its similar to the difference between .308 winchester and 7.62 nato. Aim doesn't properly label the caliber, its very likely .223.
     
  5. sneakyjesus

    sneakyjesus New Member

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    i linked the new home of the ammooracle in my post above, it's all there
     
  6. jeepilot

    jeepilot Banned

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    There's a difference in the pressures involved. That's why you can't shoot .308 out of a 7.62 nato chamber, because commercial pressures are too high.

    I think it's reversed for .223 though, and the 5.56 pressures are too high for a .223 chamber.
     
  7. Cannondale

    Cannondale OT Supporter

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    You are correct.
     
  8. Soybomb

    Soybomb New Member

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    There's a lot of talk about that (pressure and .308 v. 7.62) and I think most of it is wrong. Compare the speeds of your standard .308 and 7.62 loads. They're very similar weight bullets at very similar speeds. I don't think there is any significant difference in pressure. I think that idea comes from the pressure being measured differently between the two (piezo strain gauge measuring psi v. copper crush for cups) and people just assuming that one is 50 thousand and one is 60 thousand and clearly have to be the same units.

    That isn't to say they're the same and interchangable though. I think it comes down to the different headspacing between the two. A nato gun might have a chamber that will eat a saami 1.638 field gauge but can still safely shoot the stronger case of the nato round. Nato field guage is 1.646 (or 1.642...dont remember) and the .308 no go gauge is the same length as the nato go gauge! If you were to put a .308 round in that though you might have some serious problems. If I had an old surplus nato gun, I'd drop a .308 field gauge in it. If it doesn't close on that, I'd feel free to shot .308 rounds. If it does close on that, I would get/make a nato field gauge. If it doesn't close on that, you have a shooter but only for nato spec rounds. If it closed on that, I would cry and realize I have a decoration.
     
  9. Paul Revere

    Paul Revere OT Supporter

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    the photo of the headstamp is 5.56 :dunno:
     
  10. Soybomb

    Soybomb New Member

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    And sometimes I'm wrong and someone will just click a link that I'm too lazy to click and prove me wrong :big grin:

    I usually don't expect plinking ammo to be loaded to higher pressures, thats really all I based my guess on.
     
  11. cjj92yj

    cjj92yj Guest

    LOL, this could take a while!

    Thanks
     
  12. jeepilot

    jeepilot Banned

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    I've heard of cases of people shooting .308 out of their 7.62 and getting blown heads on the cases, and other overpressure problems. Don't know if that's due to headspacing or what, but I've heard that it will cause issues.
     
  13. A96HondaAccordCoupeEX

    A96HondaAccordCoupeEX Silver Member

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    Yes, 5.56 labeled barrel can fire both 5.56 and .223 ammo safely.

    .223 marked barrels should fire only .223 ammo.

    That's not to say it cant fire 5.56, but there will be pressure issues, and you risk serious damage to your rifle, or body injury.

    Prvi Partisan is M193 spec ammo. Which means 5.56. So yeah, you shouldnt use it in a rifle that's chambered for .223.
     

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