Been shooting and hunting for 45+ years and finally just picked a Cetme for a fun gun. Question is what to put through it? I always thought that 7.62 X 51 and .308 were the same thing. Now I find out that I may be wrong as I have seen info telling me that I shouldn't fire anything but MILITARY AMMO through these guns (no commercial, nonstandard, or reloads). Something to do with wall thickness (thicker on MIL SPEC) and sloppy specs as to sizing (much wider limitations on MILSPEC) Is this true? If so-can I reload using military brass to nato specs and if so where do I find nato specs? I already load for .308 plus others.