nothing more than the russian version of the good old 7,63 Mauser and yes the 7,63 Mauser is the grandmother of the 9 mm Parabellum. because the mauser was to long for lugers early version is was shortened to the 7,65x22 parabellum than necked up to 9 mm.

the tokarev was the cartridge for the tokerev pistol and for the other russian ww 2 submachine guns

there is no evidence for a special hot loaded sub ammo
different countrys load it hotter than other and fired in chinese C 96 pistols in very bad shape this was making problems.