ok confused

Discussion in 'Ammunition & Reloading' started by johnfs, Sep 4, 2012.

  1. johnfs

    johnfs New Member

    109
    0
    0
    i have rock river lower a bushmaster crome lined 1/9 twist upper got the upper from local gun shop he gave me 6 boxes 223 ammo bought 450 rounds 5.56 nato at walmart green tip can i use both or what kinda confused
     
  2. trip286

    trip286 New Member

    18,658
    1
    0
    What do the markings on your barrel say?

    If it says 5.56, then yes.
    If it says 5.56/.223 then yes.
    If it says "Wylde" then yes.
    If it says .223 then no.
     

  3. GaMatt72

    GaMatt72 New Member

    456
    0
    0
    Awesome link!!!
     
  4. steve4102

    steve4102 New Member

    238
    0
    0
    Note the pressures for the 5.56 and the 223 tested by Barnes. Nothing dangerous there.

    [​IMG]
     
  5. johnfs

    johnfs New Member

    109
    0
    0
    checked barrel b-mp-5.56 nato
     
  6. trip286

    trip286 New Member

    18,658
    1
    0
    Then you can shoot both. Just keep in mind your rifle will probably be more accurate with 5.56. But then again, you never know.
     
  7. johnfs

    johnfs New Member

    109
    0
    0
    ok want to say thanks for all input great sight. looking foward to shooting this often

    i havent fired one of these alot sence 1986 only 26 years have to relearn alot

    again thanks to everyone
     

    Attached Files:

    Last edited: Sep 5, 2012
  8. steve4102

    steve4102 New Member

    238
    0
    0
    Curious, why would the 5.56 Nato ammo be more accurate?
     
  9. trip286

    trip286 New Member

    18,658
    1
    0
    Because the chamber specs are just SLIGHTLY different. Meaning, the 5.56 would fit better, lending to better accuracy, as that's what it's meant for.

    That's the theory anyway. You just never can tell what any individual gun will do.

    And, I'm talking about differences that COULD be as little as .2 MOA. They could be more though.
     
  10. steve4102

    steve4102 New Member

    238
    0
    0
    You are correct that he chamber specs are slightly different, but the external dimensions of the ammo are identical.
     
  11. trip286

    trip286 New Member

    18,658
    1
    0
    And do you think that makes no impact?
     
  12. steve4102

    steve4102 New Member

    238
    0
    0
    As the external dimensions of the 223 and 5.56 are identical, how can "that" have any impact?
     
  13. USEBOTHHANDS

    USEBOTHHANDS New Member

    1,319
    2
    0
    there is a "leade" difference between the two rounds........the 5.56 round "sits" in the throat of the barrel a lil more forward, thus seatin the actual bullet into the barrel, thus givin a more accurate "jump" out of the barrel due to more, initial metal on metal contact.

    the shorter lead in the .223 round causes the actual bullet to have to close the distance between it's start position and the longer throat (because of the longer leade) of the .556 barrel. this "gap" between the two metals (still metal on metal contact, but not as much as 5.56) causes the bullet to have to "slam (if you will)" into the barrel, and thus lose a bit of accuracy.

    or that's how i see and read it.

    http://le.atk.com/pdf/223VS556.pdf

    http://www.rifleshootermag.com/2012/02/02/5-56-and-223-are-they-different/
     
    Last edited: Sep 6, 2012
  14. Eturnsdale

    Eturnsdale New Member

    1,163
    0
    0
    NATO EPVAT and SAAMI test chamber pressures in different locations. The differences in testing standards account for upwards of 20,000 psi difference. That said, NATO EPVAT tests at the case mouth, SAAMI does not. CIP tested both at the same location and came up with the same pressures.

    Question I have, does the leade difference account for the similar pressures, did CIP test both rounds in a rifle chambered for only one?
     
    Last edited: Sep 6, 2012
  15. treehugger49

    treehugger49 New Member

    421
    0
    0
    From a purely anecdotal perspective, I get much better accuracy with factory .223 ammo (Hornady) out of my RRA Entry Tactical (5.56) AR-15 compared to the M-193 and M-855 rounds I've shot from American Eagle and Winchester.

    Unscientific, I'll grant you, but it's a fact, Jack.

    If I had to guess the reason, I'd say that "mil-spec" assures a minimum level of quality and consistency, whereas commercial ammunition often meets higher QC standards.
     
    Last edited: Sep 6, 2012
  16. USEBOTHHANDS

    USEBOTHHANDS New Member

    1,319
    2
    0

    and that could very well be. :) every rifle has it's favorite ammo.