difference in 556 and 223

Discussion in 'AR-15 Discussion' started by Devin556, Oct 15, 2012.

  1. Devin556

    Devin556 New Member

    I'm sure this is probably a dumb question and I'm also pretty sure I already know the answer but I need a little reassurance. What is the difference between the .223 and the NATO 5.56?
  2. Overkill0084

    Overkill0084 Active Member

    Higher pressure in the milspec round mostly.
    Last edited: Oct 15, 2012

  3. JonM

    JonM Moderator

    The difference is the chamber. 556 has a longer lead to allow for a longer ogive on certain rounds like tracer and ap rounds like the ss109 and its newer successor.

    The pressure is the same as 223 except if you load a 556 into a 223 then the ogive is likely to press on the lands and grooves. This cause the increase in pressure that can at some point cause a kaboom. The more rounds you fire without cleaning the dirtier the throat gets constricting an already too short chamber eventually causing a kaboom.

    Some 223 are sloppier and are actually over bored and can fire the 556 with no issues due to being out of spec on the large end.

    The ogive is the part of the bullet that is rounded just behind the point.