[Mike Irwin]

First off, as I noted, each member of the Warsaw pact was expected to supply its own internal arms and ammunition needs, often from factories either established by the Soviet Union. That same pattern largely existed in NATO, as well; i.e., Czechoslovakia wasn't expected to supply Romania with ammunition or arms.

In other words, there was little expectation that Czechoslovakian ammunition would end up in the hands of its allies.

Second, there's no clear indication of just how long that 7.62 ammunition was produced. The loading parameters could easily have been changed after 1955-1957, leaving the uploaded ammunition to be consumed in training by the Czech military.

Finally, and most importantly, the Tokarev was being replaced by the Makarov in the Soviet Union by 1951-1952, prior to establishment of the Warsaw Pact. The Czechs, however, maintained the CZ 52 as their standard service weapon until well into the 1960s. As far as I know, the Czechs never fully adopted the 9x18 Makarov round, nor did they ever fully replace the CZ 52 in service until into the 1980s.

In other words, the Czechs maintained autonomy in their service handgun and cartridge WELL after their entry into the Warsaw Pact.

Given that most of the rest of the pact was using 9mm Makarov, and the only other Communist nations maintaining large front line stocks of 7.62 pistols were in Asia (North Korea and China), the issue of Czech ammo "blowing up their allies pistols" fades even farther into the background to the point where it's hardly a serious consideration.

As far as the Makarov round being adopted without modification, a couple of things could explain that...

First, the round really isn't (unlike the 7.62) capable of being uploaded to a much greater degree.

Second, indications are that the uploaded 7.62 round was to be used in both the CZ 52 and Czech submachine guns. The Makarov was only a handgun round.

Third, two words may more fully explain why... Prague Spring.