FCG installation and function
This section will show the proper installation of the FCG and how it works. First lets look at the parts and how they fit into the receiver.
The first step is to install the hammer. Put it in sideways and rotate it so that the legs on the spring are pointed down and the ears on the hammer are on the top. Insert the axis pin and lock it in place with the 3/16" "E" clip or the Sheppard's hook. The next step is to install the safety selector. Insert it from the right side of the receiver and rotate it forward and down into the fire position.
Next you will install the trigger. If you are using a US made trigger group you should be able to assemble the trigger/sear outside the receiver and drop it in. If you are using the original trigger/sear you will drop the trigger in place and start the axis pin from the left side. Make sure that the legs of the hammer/trigger spring are on top of the trigger arms in the back. The pin should go under the spring. Now insert the sear spring into the sear and lower it in place on the trigger. There is a detent in the trigger for the sear spring. Once it is in place push the axis pin the rest of the way through and lock it in place.
The FCG is now installed and you can check it for function. First you will want to ensure that the safety selector will engage the trigger. Cock the hammer back until it catches on the trigger hooks. Rotate the safety selector up until it is level with the top of the receiver. Pull the trigger, if the hammer does not release and resets when pressure is taken off the trigger the safety is functional. If the hammer drops or does not go back to full engagement you will need to add some metal to the bottom of the safety bar.
The AK FCG is operated by the the bolt/carrier moving back through recoil and then moving forward under spring pressure into battery. Once the rifle is fired the bolt/carrier will move faster than most people can release the trigger. As the bolt/carrier travels over the FCG it will push the hammer back and cause it to catch on the sear. When the bolt/carrier moves forward and the trigger is released the hammer will fall forward and be caught by the trigger hooks.
The most common errors that are made in the FCG installation are putting the hammer in backwards or leaving out the sear spring. If you have an issue with the hammer not catching after each shot check these two parts first.
CYA message: This web page is posted for informational and educational use only. Any other use of the information on this website is solely at the user's risk.