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shooting .223 out of 5.56

Discussion in 'Band of Glockers' started by Young Once, Apr 5, 2009.

  1. I was going over some ammo in my stash and I found out that there were some .223's mixed with my 5.56's. Although I haven't tried yet, is it OK to shoot .223 out of a 5.56 barrel? These bullets were just give to me and I only noticed the mix today. Thanks.
  2. akula

    akula BizDuc NM Millennium Member

    Oct 11, 1999
    Diri, Diha, Didto
    No problem on my 14.5 M4 Bushy barrel.

    Most of my .223 REM headstamped ammo were possible 'Armscor' production surplus -- Fiocchi, HSM, AP. They seemed to be loaded lower compared with the milspec M193-rated such as BMP, WCC and LC.

    Less accurate though.



    Jul 13, 2005
    SJ/The Sin City
    you should be OK. I usually have a mixed of .223 and 5.56 in my AR with barrel stamped as 5.56. what i'm wondering, since there's a little difference in their dimensions (and pressure?), if accuracy is better than the other.
  4. vega


    Sep 29, 2001
    As I understand if your barrel is stamped 5.56 you can shoot both .223 and 5.56 and if your barrel is stamped .223 you should only shoot .223s.
  5. 93GT

    93GT The Ogre

    Jul 6, 2002
    I just shot under an inch group at 100 yards from my 5.56 chamber 24 inch bull barrel AR-15 with 75 gr hornady .223 ammo. It may hurt accuracy a bit, but it still seems plenty acceptable to me.
  6. Whew. Thanks for the info, guys. For a while there I thought that that was unacceptable. Happy easter to all in advance!
  7. dinggaling

    dinggaling APO Traveler

    Jul 4, 2004
    Rainbow Clubhouse
    CORRECT!!!! :cool:
  8. isuzu


    Jul 3, 2005
    North America
    You may have a different point of impact especially with 40 gr .223, but it should not be bad. Rock River Arms' ARs have a Wylde chamber where you can use both .223 and 5.56mm.
  9. wunder9


    Mar 9, 2003
    Problem with this is that the marking on the barrel may not be the actual chamber dimensions. I've read there are instances that 5.56 marked barrels are actually .223 chambered and vice-versa.

    The ideal way to check is to use a gage but I don't know anyone who has one. Instead I check the primers on the fired brass. I read that .223 chambers can over pressure 5.56 ammo & cause the primer to bulge or pop out.
  10. I shoot .223 all the time from my Bushmaster barrel, no problems, except for some denting on the case mouth from the ejection. What you don't want to do is shoot 5.56 from a .223 barrel, if you do so at the very least the case will be stuck in the chamber, mallet time.:supergrin:

    Difference is that 5.56 is loaded hotter than .223. Military BMP is the hottest (and most accurate) of all, approx. 3,300fps from a 20-inch barrel, while .223, especially the HSM stamp, barely breaks 3,000fps from the same barrel.