The difference of the OD at 16 1/2" vs 17 3/8"(step up right behind the oem fsb) is nominal and at the M15(.58") so yes, you would need an annular cutter to turn down the barrel to M14(.51") at least 1 1/8" deep for your modded fsb and the MB. Then the threading tool and keep in mind, only the AK uses LH thread others, like the yugo SKS, are RH thread and there may be more options available in MBs in RH thread.