difference between .223rem and 5.56nato

Discussion in 'Ammunition and Reloading' started by khoff, May 1, 2012.

  1. khoff

    khoff New Member

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    next time you wonder what exactly is the difference between .223 rem and 5.56 nato the answer is 12,000 psi. .223 rem is rated at about 50,000 psi and 5.56 nato is rated at about 62,000 psi. i think there also might be some very slight chamber dimentional differences.i very much like the .223-5.56 cartridge. it is easy to shoot, accurate, and effective.it is also economical, unlike .338 lapua which costs about 5.00 dollars a round to shoot.
     
  2. Talyn

    Talyn New Member

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    I wasn't even aware until recently (though I should have looked) that the 223 and 5.56 were pretty much the same.


    Some people elsewhere were talking about this and I picked it up.

    I don't remember where though.
     

  3. Shooter

    Shooter Premium Member

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    Buy your rifles in 5.56 and you can shoot both. 223 chambers may cause higher pressures for 5.56. Simply put
     
  4. Urban_Redneck

    Urban_Redneck New Member

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    SAAMI 223 max is 55,000 psi. SAAMI 5.56x45 data I cannot find.

    CIP (European proof standard) Piezo electric device, spec is 55,000psi for the .223 and 62.000psi for 5.56.

    I believe the cartridge cases are the same dimensionally, the difference is the throat or leade. In 5.56 marked barrels the leade is longer allowing 62-75 projectiles to be used without causing dangerous pressure spikes.

    YMMV
     
  5. Grocerystore_ninja

    Grocerystore_ninja New Member

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    that's because 5.56 nato is not a saami cartridge
     
  6. manChild_762

    manChild_762 New Member

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    Maybe this will help explain the difference. http://www.luckygunner.com/labs/5-56-vs-223/

    But yea Sammi does not have any specs for the 5.56, so in a sense it is the most popular wildcat round in the world. Joking aside, they are more or less the same, but 5.56 Lake City cartridges are said to have a little more volume than 223 remmington cartridges. Which can be a big deal if your reloading. Something I am starting to get into. It is interesting to note that they publish which manufacture they use for the reload data, so it seems to me that it's more manufacture dependent than specs since everyone's specs for the 223 wylde is different by a little bit.
     
  7. ETH77

    ETH77 Premium Member

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    Not only is the neck slightly different, the brass is thicker, allowing for the 9K PSI difference. If you reload with XBR, you have essentially the same as NATO. There's a Swiss powder used by the Swiss for their ammo, on which the SIGs are tested. It's available sometimes here in the US.
     
  8. Hektor

    Hektor New Member

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    There are a few different reamers that gunsmiths can use to make a .223/5.56 shoot. As I recall,a Wylde chamber allows a slightly longer throat. A barrel maker I know uses different bore buttons also. I believe the USMU and the All Guard team has their own reamer. (anyone could use it, I suppose) There was a study of all .223 brass with their different capacities that was posted on 6BR.com. http://www.6mmbr.com/223Rem.html
     
  9. manChild_762

    manChild_762 New Member

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  10. Branth

    Branth New Member

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    I wouldn't bet my life on this, but I've heard the pressures are pretty similar, and that difference comes from the methods they use to measure the pressure - SAAMI uses CUP, which isn't exactly similar to PSI, and on one the pressure is taken from the case wall, and the other the case neck. It's pretty hard to compare the two accurately.

    My chamber's designed to shoot both, though, so I don't have to sweat it.