fordgalaxy and 1biggun,
the mod is to the mag falower. the link is on saiga-12 forms. the member that did the grunt work is dizang. he will make the changes for a small fee, however you could make the changes as he does state this in his post. photo #2,and3 are the modes for the saiga not sure if they are needed on a non saiga build.
I have not made the changes yeat (still working on other build) but have not found a bad posting after the change was made. muttman