I talked to Ken Roberts the President Red Star Arms via email and was told that a standard FCG works and that the special one they make is for the VEPR line of guns not the Saiga.
I picked up my .308 Saiga today! One thing I didn?t know was that they are made with 16 and 22 inch barrels. I got the 16? and it?s the only length that CDNN carries I guess. I?m impressed with the quality of the gun for the price paid, ($265 w/shipping) and I like the fact that they added a bolt hold-open button next to the trigger. I found that the piston seems to be 3/16 shorter than the AMD-63 but I think a standard US made replacement part should work because there?s plenty of room (length wise) in the gas block. With the 16? barrel it makes a nice short home-defense type weapon and has a very heavy barrel that makes it feel good in your hands. The only drawbacks are the rear stock because it?s hollow and the fact that the magazines are only 8-rd and cost $25 each. For now I?m keeping the stock but will fill it with expanding foam to cut noise and for a more solid feel. I?ll see if I can convert an FAL or M-14 Mag to fit the gun, Just don?t know if I can make that work, but having 20 rd?s sounds better than 8 to me.
Comparing the Saiga to my AMD-63?s I find a few things different,
1. Larger bolt head with different extractor and larger cam, carrier made to fit larger cam.
2. Limiter block on return-spring guide to limit max rear position of bolt carrier in recoil.
3. Firing pin is spring-loaded and rear of bolt has smaller diameter.
4. Rear trunnion is a little different but should work the same.
5. Love that bolt hold-open. I think we can add this to our builds with a little work. It looks simple.
6. 90 degree gas block. Who cares, it looks great.
7. Receiver has bulges like a Dragunov does on each side in front.