Zero an M4 or M4A1 Carbine
071-100-0001
Conditions: On a 25-meter range, given an M4 or M4A1 carbine; 18 rounds of 5.56-mm ammunition; a 25-meter zero target; and sandbags for support.
Standards: Fire and adjust sights on the M4 or M4A1 carbine so that a three-round shot group(s) centered on the white dot at the center of the zero target used 18 rounds or less.
Performance Steps1.Establish a mechanical zero for the carbine.
a.Flip up the unmarked, long-range aperture on the rear sight.
NOTE: Do not move the front sight post at this time.
b.Center the rear sight aperture by turning the windage knob left or right. Align the index mark on the 0-2 aperture with the center line on the windage scale and the mark on the receiver.
c.Rotate the elevation knob counterclockwise (down) until the range scale stops on the 300-meter mark (6/3). Take the rear sight all the way down until you hear the last whole "click" before it bottoms out.
d.Rotate the elevation knob two clicks clockwise (up) past the 300-meter setting. Leave elevation knob on the 300-meter setting (6/3). Make any further elevation corrections to the front sight post only.
NOTE: The sight picture is obtained by aligning the rear sight and the front sight with the proper aiming point for your target. The sight picture depends on sight alignment and placement of the aiming point.
2.Establish a correct sight picture.
a.Check to ensure the carbine side of the 25-meter target is facing you.
b.Assume a supported fighting position.
c.Load the weapon.
d.Align the sights.
(1)Center the top of the front sight post in the center of the rear sight.
(2)Draw an imaginary horizontal line through the center of the rear aperture so that the top of the front sight post touches the line.
(3)Draw an imaginary vertical line through the center of the rear aperture that bisects the front sight post.
(4)Verify the sight picture.
NOTE: When you concentrate on the front sight post, the rear sight aperture will be blurred.
e.Align the aiming point.
(1)Aim at target center.
(2)Position the top of the front sight post center mass of the scaled silhouette target.
(3)Confirm that an imaginary vertical line drawn through the center of the front sight post splits the target.
(4)Confirm that an imaginary horizontal line drawn through the top of the front sight post splits the target.
3.Establish a three-round shot group 4 centimeters or less in diameter.
a.Fire a three-round shot group at the target.
b.Triangulate the shot group on the target.
c.Repeat Steps a and b until the shot group is 4 centimeters or less in diameter.
NOTE: Vertical and horizontal lines divide the target. It also has pictures of the front and rear sights with a direction arrow to assist you with adjusting the sights.
4.Adjust the sights to move the shot group to the white dot in the center of the target.
NOTE: Do not adjust the sights if the shot group meets the standard.
a.If your shot group is not in the center of the bull's eye, use the squares on the target to calculate the number of clicks required to move your next shot group close to the white dot. The numbered squares around the edges of the target each represent a click on the sight.
(1)Elevation. One click will move the strike of the bullet up or down one square on the target sheet.
( a)To move the shot group down, rotate the front sight post clockwise.
( b)To move the shot group up, rotate the front sight post counterclockwise.
(2)Windage. Three clicks will move the strike of the bullet one square left or right.
( a)To move the shot group to the left, turn the windage knob counterclockwise.
( b)To move the shot group to the right, turn the windage knob clockwise.
b.Keep track of adjustments.
c.Fire a three-round shot group.
d.Repeat step a until the shot group centers on the white dot in the center of the target.
e.Rotate the rear sight elevation knob counterclockwise (down) two clicks to the 300-meter setting. The weapon is zeroed for 300-meter battlesight.
f.Compute and record battlesight zero. See the example shown in Figure 1.
Figure 1. Example of battlesight zero computation.
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Evaluation Preparation: SETUP: On a 25-meter firing range, the Soldier has an assigned rifle and magazine. Give the Soldier 18 rounds of 5.56-mm ball ammunition, and a sandbag for support.
NOTE: You can train rifle marksmanship skills using any and all rifle marksmanship training devices (such as Weaponeer, Basic Rifle Marksmanship, DVC 07-57). The live-fire evaluation of a Soldier's ability to zero the rifle requires firing on the standard zero range. The performance of this task for the common task test (CTT) can be done in conjunction with live-fire on the standard zero range or during a unit weapon qualification firing cycle.
BRIEF SOLDIER: Tell the Soldier to battle sight zero the rifle using no more than 18 rounds. Provide a scenario that requires the Soldier to establish a mechanical zero.
1.Established a mechanical zero for the carbine. / —— / ——
a.Flipped up the unmarked, long-range aperture on the rear sight.
b.Centered the rear sight aperture by turning the windage knob left or right.
c.Rotated the elevation knob counterclockwise (down) until the range scale stopped on the 300-meter mark (6/3).
d.Rotated the elevation knob two clicks clockwise (up) past the 300-meter setting.
2.Established a correct sight picture. / —— / ——
a.Checked to ensure the carbine side of the 25-meter target was facing you.
b.Assumed a supported fighting position.
c.Loaded the weapon.
d.Aligned the sights.
e.Aligned the aiming point.
3.Established a three-round shot group 4 centimeters or less in diameter. / —— / ——
a.Fired a three-round shot group at the target.
b.Triangulated the shot group on the target.
c.Repeated steps a and b until the shot group measured 4 centimeters or less in diameter.
4.Adjusted the sights to move the shot group center to the white dot in the center of the target. / —— / ——
a.If your shot group was not in the center of the bull's eye, used the squares on the target to calculate the number of clicks required to move your next shot group close to the white dot. (The squares are numbered around the edges of the target to help you see how many clicks you need to move the shot group to the white dot.)
b.Tracked adjustments.
c.Fired a three-round shot group.
d.Repeated until a shot group centered on the white dot in center of the target.
e.Rotated rear sight elevation knob counterclockwise (down) two clicks to the 300-meter setting.
f.Computed and recorded battlesight zero.
Evaluation Guidance: Score the Soldier GO if all performance measures are passed. Score the Soldier NO-GO if any performance measure is failed. If the Soldier scores NO-GO, show the Soldier what was done wrong and how to do it correctly.
ReferencesRequired / Related
TM 9-1005-319-10
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