All I have is hearsay from elsewhere on this same question...their concensus is usually accepted as "truth". Perhaps someone with actual experience will reply, or not...perhaps this is considered as thread hijacking . Unfortunately the "word " was NO to interchangability...not stated as the reasons why or I simply didn't bother to remember why. I have the Saiga 308 & DO believe the FBMGs are the mags to use as being less bulky than the Surefires & more reliable. A lot of people run Surefires and say only the 25 rders have issues...but they are HUGE.