Depends on Situation
If my family goes with me, 7.62x39 is the only caliber, other than .22LR, that feeds enough weapons in order for each of us to have one. Better to have a single common caliber, especially one for which I have thousands of rounds.
Of course, my priority in such a situation would be to AVOID going into a battle, while using the firearms only when absolutely necessary, such as in self-defense or hunting. I don't pretend to be capable of anything more than that.