There are some good cheap defense loads out there.
If I recall, Wolf makes a hollow point 7.62x39mm load that works very well and expands greatly in tissue. Very effective against an enemy attacker, and can be had for about $25 cents a shot.
Rifle rounds require much less to be effective at stopping human attackers than do pistol rounds. Rifles are rifles, pistols are pistols.
I wouldn't feel bad, at all, about ANY x39 round doing what is required/reasonably expected.