This is the continuing sage of the bolt problems of my EM352 (NDM-86). The problem is that it had the firing pin tip modified to stop it piercing primers before I bought it. This seems to have created the problem that it will no longer fire milsurp ammo with hard primers. It fires the 1st & 2nd rounds - then only lightly bruishes the primers after that. Have been fortunate to find a Russian TIGR firing pin & return spring - but they won't fit inside the Norinco bolt. The FP hole in the Chinese bolt is a slightly smaller dia hole than the TIGR's. Next stage is to source a 308 TIGR bolt & try that, but I don't know how that will affect headspacing. Does anyone have any other ideas please?