Point of Impact - 50 to 100 yards

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  • lwminton
    Warrior
    • Nov 2014
    • 143

    Point of Impact - 50 to 100 yards

    If I zeroed a scope at 50 yards (load 120 gr bullet and 31.3 CFE 223), would the point of impact at 100 yards be higher or lower and by roughly how much?
  • Drillboss
    Warrior
    • Jan 2015
    • 894

    #2
    Calculators show that a 50 yd zero is pretty much spot on at 100 yds (assuming 2500 fps muzzle velocity).

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    • Klem
      Chieftain
      • Aug 2013
      • 3507

      #3
      Assuming 2500fps/120AMax, scope height 2.5" above bore and a 50yd zero your round will impact 1" high at 100yds.
      (ref; JBM Ballistics, online)
      Last edited by Klem; 10-27-2015, 03:50 PM.

      Comment

      • Drillboss
        Warrior
        • Jan 2015
        • 894

        #4
        Good point. I left the scope height at the default 1.5".

        Comment

        • LRRPF52
          Super Moderator
          • Sep 2014
          • 8569

          #5
          You need to know:

          * Optic height above bore
          * Projectile weight
          * Muzzle velocity
          * BC
          * Temperature
          * Barometric pressure

          When I zero at 6600ft elevation, then come down to 4400ft, the POI shift is pretty big. I just did that this past week, and the zero stop would't let me go low enough to compensate for the low POI at 4400ft.

          50yd zeros normally print high at 100yds though, with your scope height and mv being the biggest factors in how high.
          NRA Basic, Pistol, Rifle, Shotgun, RSO

          CCW, CQM, DM, Long Range Rifle Instructor

          6.5 Grendel Reloading Handbooks & chamber brushes can be found here:

          www.AR15buildbox.com

          Comment

          • lwminton
            Warrior
            • Nov 2014
            • 143

            #6
            Is the scope height measurement the distance from the center of the scope to the center of the bore?

            Comment

            • LRRPF52
              Super Moderator
              • Sep 2014
              • 8569

              #7
              Originally posted by lwminton View Post
              Is the scope height measurement the distance from the center of the scope to the center of the bore?
              Yes. I use calipers.
              NRA Basic, Pistol, Rifle, Shotgun, RSO

              CCW, CQM, DM, Long Range Rifle Instructor

              6.5 Grendel Reloading Handbooks & chamber brushes can be found here:

              www.AR15buildbox.com

              Comment

              • lwminton
                Warrior
                • Nov 2014
                • 143

                #8
                Thanks all.

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