M13 AT4 Sights
The fact that the M136 AT4's front and rear sights resemble those of the M16-series rifle makes using the M136 AT4 easier.
Sights on the M136 AT4
The front sight has a sight blade with a center post and left and right lead posts. A semicircular white line helps you obtain the proper sight picture. To open the front sight cover, press down on it and slide it backward until the sight pops up.
The rear sight has a sight blade, range adjustment knob, range scale, 2-mm peephole for normal daylight visibility conditions, and 7-mm peephole for limited visibility conditions. To open the rear sight cover, press down on it and slide it forward until the sight pops up.
The M136 AT4 can be fitted with the AN/PAQ-4C, AN/PEQ-2, or the AN/PAS-13, when used with the nightsight mounting bracket (NSN 5340-01-391-3004).
- The leaf blade that covers the 7-mm peephole has its own tiny 2-mm peephole. To uncover the 7-mm peephole, pull the bottom of the leaf blade out slightly and rotate it right and up. To cover the 7-mm peephole, rotate it back down and ensure the leaf blade is seated. The range indicator scale is indexed from 100 to 500 meters in 50-meter increments.
- To increase the range setting beyond 200 meters, turn the range adjustment knob clockwise, or vice versa. You must remember to reset the range to 200 meters when you close the rear sight. Otherwise, closing the sight cover will break off the rear sight.
Adjusting the rear sight range setting on the M136 AT4