There is Tokarev ammunition, and then there is Tokarev ammunition
The original stuff was close to the C96 loads, but later versions were beefed up for submachiegun use. Same thing happened with the 9x19 that was loaded for the Sten gun, etc..
In the 1970s Interarms sold repackaged Russian 7,62 Tok of the milder variation as ammunition specifically for the C96. I shot a few of those boxes without ill effects. Only problem was the corrosive primer, so a good barrel scrubbing was needed after each session.
So, not all Tok is bad, but not all Tok is good either. Which makes it wise to avoid using it in a C96 unless the package is sealed and clearly marked for C96 use.
Hope this makes sense