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Can .223 be used in 5.56?

Discussion in 'Rifle Country' started by nstyn8, May 18, 2008.

  1. nstyn8

    nstyn8 New Member

    I have been wondering if I should go with the 5.56 nato or the .223.
    I heard that you can use the .223 in a 5.56. But not the other way around due to pressure from the different rounds. Is this true or should the rifle be specific to except both or am I just uninformed? Please let me know what I should do. I don't want to damage a some gear by being uninformed.:confused:
  2. MaterDei

    MaterDei Well-Known Member

    You are correct. If you want to be able to shoot both get a 5.56.
  3. AR-15 Rep

    AR-15 Rep Well-Known Member

    Almost all AR style rifles are chambered 5.56mm it is kind of the industry standard.
  4. jdc1244

    jdc1244 Well-Known Member

    Just make sure when shopping that a given rifle will chamber both; some rifles will be marked for .223 but can also chamber the 5.56, like the CZ 527.
  5. lmccrock

    lmccrock Well-Known Member

    There is another chamber called the Wylde which is usually seen in some Rock River rifles. It is considered a good intermediate chamber and will shoot both.

    This may be more data than you want, but here is a comparison of 223 vs 5.56 chambers.

  6. Zach S

    Zach S Well-Known Member

    Something else to note here is that some ARs are marked .223 on the lower, however the bbl is marked 5.56.
  7. ambidextrous1

    ambidextrous1 Well-Known Member

    Please clarify this for me:

    Is it safe to assume that it's safe to fire a 5.56mm cartrideg in a .223 if it can be chambered? :confused: :eek:
  8. Gingerbreadman

    Gingerbreadman Well-Known Member

    Check with the manufacturer to see if you can shoot 5.56 in a .223 gun.

    A 5.56 bbl will fit .223. Not necessarily the other way around.
  9. s2brutus

    s2brutus Well-Known Member


    "They" say not to shoot 5.56 in any rifle chambered specifically for .223, but as is the case most of the time, most of this is likely just legal azz-covering.

    My H&R Handi-rifle is chambered in .223, but I've shot plenty of 5.56 NATO in it. You CAN tell the difference because it won't extract and eject 5.56. The cases have to be knocked out with a light tap from a cleaning rod. But, if you note the amount of "meat" in the chamber area of a Handi-rifle in .223, there's no way 5.56 is going to hurt it.

    Just having to tap the case out is enough of a pain in the azz to keep me from shooting 5.56 in it unless I just have to, but if I had to shoot 5.56 in it I wouldn't lose a minute's sleep over it.

  10. fletcher

    fletcher Well-Known Member

    For DPMS, I know you should not do that. Can't speak for other manufacturers.
  11. JCUMM2

    JCUMM2 Active Member

    "They" say not to shoot 5.56 in any rifle chambered specifically for .223, but as is the case most of the time, most of this is likely just legal azz-covering.

    No It is not. The 5.56 cartirdge has somewhat larger dimensions and runs at significantly higher pressure. Many Ar15s chambered for 223 do not cycle well and blow out primers if 5.56 ammo is used. This is particularly true for rifles with minimum sized 223 target chambers. Bushmaster and Compass Lake National Match chambers in particular do not handle 5.56 well. Make sure you know what chamber you have before using any 5.56 ammo. This is not just hearsay. It is personal experience is shooting match ARs in highpower competition. I have seen many people have trouble in matches trying to shoot 5.56 ammo in target chambered ARs.
  12. benson2255

    benson2255 Member

    listen to jcumm2 he is spot on. no 5.56 in .223 but should be able to .223 in 5.56. best bet, manufacturers recommendation. They usually know what they are talking about and what their gun is designed for.
  13. s2brutus

    s2brutus Well-Known Member

    Yeah, benson, I hear ya'.......

    They'll also tell you not to shoot 7.62 NATO in a .308 when commercial .308 maximum pressures are up to 12,000 psi HIGHER than 7.62 NATO avg. max. pressures.

  14. RockyMtnTactical

    RockyMtnTactical Well-Known Member

  15. AR15barrels

    AR15barrels Well-Known Member

  16. AR15barrels

    AR15barrels Well-Known Member

    Doh, doubletap...
  17. Onmilo

    Onmilo Well-Known Member

    Same thing goes for shooting .223 Rem in a 5.56 chamber as shooting .308 in a 7.62X51 chamber with a notable exception.

    You can use any bullet weight and load in a 5.56 chamber as long as the twist rate can accomodate the bullet weight.

    The 7.62X51/.308 gets a bit more complicated because .308 commercial ammunition is loaded to higher pressures in some loads and not really recommended for shooting in most 7.62X51 chambered rifles.

    The big problem comes when people try to reload commercial ammunition cases that have been fired in Mil-Spec dimension chambers.

    The additional case stretching causes the thinner commercial cases to crack and seperate at a much faster rate than the thicker, larger dimension military cases.

    If you reload you really need to take the time to seperate commercial cases from military cases and anneal the commercial cases prior to reloading them.

    If you don't, then buy a broken shell extractor tool and keep it handy, you will likely need it sooner than later.
  18. chris in va

    chris in va Well-Known Member

    Which begs the question.

    Why did they come out with .223 that is slightly different from 5.56? .308 isn't like that.
  19. Ridgerunner665

    Ridgerunner665 Well-Known Member

    The military demanded 3,240 fps from a 55 grain bullet....from a 20 inch barrel...thats why.

    It was Remingtons idea to "tone it down" in civilian trim...after all they were only trying to do slightly better than the 222 Remington...or equal the 222 Rem. Mag.

    Uncle Sam demanded more.
  20. Onmilo

    Onmilo Well-Known Member

    .308 is different from 7.62X51 by the length of the headspace dimensions and the thickness of the cartridge case walls, commercial cases being thinner.

    .223 Remington is different from 5.56 by the length of the throat leed and the thickness of the cartridge case walls, commercial cases again are thinner than 5.56 though pressures usually run lower in commercial loadings.

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