I have an M70AB2 kit rifle that came with the original surplus FCG.  I've read that one can use the original trigger + rate reducer and spring to keep it from going rock and roll.  Obviously, the receiver is not drilled for an auto sear.  I'm trying to save $70-$100 by reusing the original trigger instead of buying an ALG.

For the life of me I can't figure out how to install the rate reducer spring.  Do you guys have a guide on chopping the tail or notching the safety so as to use full retard FCG parts but keep it from ever being able to go rock and roll?

I understand that the fcg parts were on the "must be replaced list" for a rifle build.
But not on the "must be replaced list" for a pistol build.
I built a pistol and modified the fcg to single shot only. If I remember correctly I just compared the full auto set and ground off the parts that did not look like the after market simiauto types. There are many good pictures of simiauto fcg on Google if you do not have one in hand. Google tapco ak47 fcg, look for the image of the fcg disassembled.
Looking at some photos I think it is just the disconnector that has a section ground off,
The disconnector has a pointed end, then the hole, then the head and a stepped tail. The stepped tail is missing on simiauto ones.

Most replaced the trigger parts to comply with 922R.

With the lack of US made parts you only had a few choices.


PSA has a group here for $40

get rid of the rate reducer spring. install the trigger, disconnector, hammer, then use a retainer plate. MUCH easier.

also, your fire control group is NOT going to go "rock and roll" without a rate reducer ... without that 3rd hole and the auto sear it's just going to fire semi auto. ONLY thing negative about some of the full auto fire control groups that are surplus is the back of the disconnector has a tail on it.. it's designed to hit the back bottom rivet or the bottom of the receiver and help the trigger bounce back. long story short, it can cause trigger slap when in semi auto mode. IF that happens, all you do is take a dremel or a file and shave that tail back. Other than that, there really is no difference between a full auto fire control group in a semi auto gun, and a semi auto fcg in a semi auto.