M13 AT4 Firing Mechanism, Safeties and Weapon Function
The weapon cannot be fired until all three safeties have been disengaged.

Posted Sunday, October 30, 2005

The function of the M136 AT4 must be discussed along with its firing mechanism and safety features. The firing mechanism is mechanical and consists of a red trigger button, an enclosed firing rod and spring, and three safety devices: transport safety pin, cocking lever, and the forward safety. The weapon cannot be fired until all three safeties have been disengaged.

Transport Safety Pin:

The transport safety pin blocks the firing pin from striking the cartridge percussion cap. To disengage this pin, pull it outward and then release it.

When the cocking lever, which is attached to the firing rod, is in the SAFE position, the firing rod and the trigger cannot touch. To cock the M136 AT4, push the lever forward and rotate it downward and to the right with your right thumb. This causes the hooks on the front of the firing rod to catch and hold the red trigger button.

The forward safety is on the front end of the firing mechanism and is connected to a steel rod with a bent end that blocks the firing rod from striking the firing pin. To fire the M136 AT4, hold down the forward safety so the firing rod can strike the percussion cap and ignite the propellant when you push the trigger.