How to Use the Horus H37 Reticle

The Horus H37 is an advanced mil-incremented reticle used in powerful telescopic riflescopes. Intended for ultra-long range military shooting, the H37 features a detailed target grid that displays graduated vertical and horizontal scales marked in units of milliradians (or "mils") with a sub-scale marked every two-tenths of a mil. Use the reticle's mil-scale markings to calculate range-to-target. Unlike standard mil-dot riflescopes, however, scopes using the H37 reticle do not need to be adjusted for windage and elevation. After calculating changes in point-of-aim for range and wind conditions, you simply hold the appropriate point on the reticle's target grid on target then fire.

Things You'll Need

  • Riflescope with H37 reticle
  • Cartridge-specific ballistic data card
  • Spotter (optional)
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Instructions

  1. Determine Range

    • 1

      Align the center of the reticle's cross-hairs at the bottom center of your target. Note that you must know the approximate height of your target (in meters) in order to determine the range. Military torso targets, for example, are typically one meter in height.

    • 2

      Count up the mil-incremented scale along the vertical axis of the reticle until you reach the top of your target. Use the sub-scale markings on the H37 reticle to measure the target to the nearest one-tenth (0.10) of a mil. Record your mil measurement.

    • 3

      Calculate the range-to-target using the formula:

      Range = (Target height / Mil count) x 1,000.

      As an example, if your count on a target one meter in height was 0.7 mils, the range calcualtion is approximately 1,428 meters:

      (1 meter / 0.7) x 1,000 = 1,428.57 meters

    Align Target Grid

    • 4

      Refer to the ballistic data card for your specific ammunition to find the range value that matches your range finder calculation. Ballistic data cards are painstakingly prepared in advance and indicate which markings on the lower target grid should be used at any given range-to-target.

    • 5

      Align the center of the target with the range, marking on the vertical axis of the lower target grid that matches your ballistic data.

    • 6

      Estimate, or have your spotter measure, wind speed and direction. Refer to your ballistic data card to find the wind correction value that matches your range-to-target.

    • 7

      Align the center of the target with the horizontal adjustment, marking on the target grid that matches the value found on your ballistic data card. Do not alter the vertical alignment of the target grid. To compensate for wind coming from the left, adjust into the right side of the target grid. Use the left side of the target grid to adjust for wind coming from the right.