WHAT DOES MILITARY SURPLUS GUNS MEAN?

The Russkis created a slightly larger bullet (9x18mm Makarov) for it and then told all the satellite states to produce a gun like it, which can be how you have the FEG PA-63, CZ eighty two and PA64 military surplus pistols.How does one come across them? In addition to local gunshops with the affinity for surplus guns, excellent sources to shop areT