I've never lacked confidence in .380 ACP, assuming a bullet constructed for the purpose you seek to fulfill. Hard cast is going to drive deep. A well designed hollow point is going to penetrate sufficiently, while also nicely expanding. I have no qualms about carrying a .380 from time to time.
Now, a .32 ACP is another story completely. That's closer to the performance realm of the .25 ACP than it is to the .380 ACP. Even the .32 ACP satisfies the first rule of gun fighting, however.
