• Weapon is zeroed prior to training.
• Individual knows how to adjust for wind and gravity.
• Individual can manipulate the rear sight for different ranges.
The trainer sets up a range estimation course using E-type silhouettes at ranges from 100 meters to 700 meters. Individuals practice on this course until they find the method that works best for them. Once individuals have had time to practice, trainers test their ability to estimate range. The firer is given six targets. He must estimate the range within 50 meters of the actual range to receive a GO. The firer must estimate range correctly six out of six targets to move on to the next portion of this phase.
1. Methods of Range Determination - SDMs can use five different methods of range determination:
• 100-meter unit-of-measure method.
• Range card method.
• Front sightpost method.
• Appearance of objects method.
• Combination method.
a. 100-Meter Unit-of-Measure Method - To use this method, the SDM must be able to visualize a distance of 100 meters on the ground.
• For ranges up to 500 meters, the SDM determines the number of 100-meter increments between the two objects he wishes to measure.
• Beyond 500 meters, he must select a point halfway to the object, determine the number of 100-meter increments to the halfway point, and then double the number.
NOTES: See earlier range determination post for more information about this method of range determination. For example, terrain with much dead space limits the accuracy of the 100-meter method.
b. Range Card Method - SDMs use a range card to quickly determine ranges throughout the target area. Once a target is detected, the SDM determines its location on the card and then reads the proper range to the target.
c. Front Sightpost Method - Using the front sightpost as a scale is another method of estimating range. This method can be used for a quick on-the-spot estimation and engagement.
• If a man-sized target is ½ of the width of the front sightpost, he is approximately 300 meters away.
• If a man-sized target is the width of the front sightpost, he is approximately 175 meters away.
d. Appearance of Objects Method - This method of range determination is based on the size and visible characteristics of an object. To use this method with any degree of accuracy, the SDM must be familiar with the appearance and visible detail of an object at various ranges. Some common guidelines can be used to determine the range of a human target:
• At 200 meters, a human target is clear and details can be seen.
• At 300 meters, the target is still clear, but no details can be seen.
• At 400 meters, the target’s outline is clear; however, the target itself is blurry.
• At 500 meters, the body tapers and the head disappears.
• At 600 meters, the body resembles a wedge shape.
e. Combination Method - In a combat environment, perfect conditions rarely exist. Therefore, only one method of range estimation may not be enough for the SDM’s specific mission. By using a combination of two or more methods to determine an unknown range, an experienced SDM should arrive at an estimated range close to the true range.
2. Three Factors Affecting Range Estimation (Nature of the Target, Nature of the Terrain and Light Conditions).
a. Nature of the Target - The nature of the target affects its perceived range:
• An object with a regular outline, such as a house, appears closer than one with an irregular outline, such as a clump of trees.
• A target that contrasts with its background appears to be closer than it actually is.
• A partly exposed target appears more distant than it actually is.
b. Nature of the Terrain - The contour of the terrain affects the observer's ability to estimate range:
• As the observer’s eye follows the contour of the terrain, he tends to overestimate distant targets.
• Observing over smooth terrain, such as sand, water, or snow, causes the observer to underestimate distant targets.
• Looking downhill, the target appears farther away.
• Looking uphill, the target appears closer.
c. Light Conditions - Light conditions affect range estimation:
• The more clearly a target can be seen, the closer it appears.
• When the sun is behind the observer, the target appears to be closer.
• When the sun is behind the target, the target is more difficult to see and appears to be farther away.
3. Elevation Knob Training - Elevation knob training involves nothing more than being able to adjust the rear elevation knob for the various ranges that the SDM must engage. With this knowledge, he can better determine his range settings for the different distances between the 100-meter adjustments. The rear elevation knob adjusts the point of aim--
• From 300 to 800 meters on the M16A2.
• From 300 to 600 meters on the M16A4 and M4.
a. Conduct - During elevation knob training, the firer determines the number of adjustments (clicks) between the different range settings on his rear elevation adjustment knob (Tables 7-30 and 7-31). Once the firer understands how to set the proper point of aim for his target using his rear elevation knob, the instructor/trainer has him conduct another range estimation course. This time, the instructor/trainer has him estimate the range and set the rear elevation for the range that he has estimated. The firer must estimate range and set his rear elevation knob properly six out of six times to receive a GO. If the firer receives a NO GO, the trainer recommends retraining, retesting, or possible removal from the course.
b. Once the firer has an understanding of range estimation and sight manipulation, he can begin the live-fire training exercise (Table 7-32). The firer will be given 20 rounds in which to engage 20 targets at ranges from 100 to 500 meters using mechanical sight adjustments.