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Zero difference between 223 and 5.56

Discussion in 'Caliber Corner' started by TrueGunNut, Aug 23, 2010.

  1. TrueGunNut


    Apr 28, 2005
    Austin, Texas
    I am going to be zeroing my 1.5x ACOG for 50 yards. I have both 5.56mm and .223 ammo in 55 grain FMJ. If i sight my gun in with the 55 grain 223 will it be "more or less" zeroed if I load xm193? or vice versa?

    Thanks :cheers:
  2. Depends upon velocity of the loads, but it should be pretty close.

  3. TrueGunNut


    Apr 28, 2005
    Austin, Texas
    So, if I am using IMI M193 5.56mm, Winchester Q3131 5.56mm, PMC .223 it should be close enough that I do not need to re-zero. Correct?

    How about if I load up 62 grain XM855? Zerod at 50 yards, if I shoot out to 200 or so yards will it be "OK" also?

  4. Brucev


    Jul 19, 2009
    In bullseye competition, you might have a small concern. For anything you might otherwise use 5.56mm FMJ on, no worries.

    If you zero w/ 62 gr. XM855 you will be fine at 200 yds. Later on you might want to "tweak" the zero a smidgen if the group center is not precisely where you want it to be.

  5. How much precision are you needing?

    Any time you change ammo your point of impact is going to move a little bit. If you are head shooting prairie dogs at 300-400 yards it's going to make a big difference. If you are talking minute of felon accuracy (keeping your hits in the chest of a man) out to 200 yards it shouldn't matter.

    You can get a pretty good estimate of the difference in elevation between the rounds you listed by entering the data into a ballistics calculator like this one:
  6. BleedNOrange

    BleedNOrange Go Vols

    Jan 31, 2009
    Volunteer State
    I threw an old scope on the AR a few weeks back and zeroed it at 50yds. I was shooting a 6in metal plate at 300yds and would hold over about 4inches. It would hit everytime with .223 55 gr and 5.56 55gr and 62 gr...Even the cheap wolf ammo was right on target. The differences are minimal unless you are going for extreme precision.
  7. TrueGunNut


    Apr 28, 2005
    Austin, Texas
    Sounds good, BleedNOrange.