Unfortunately hollowpoint expansion in a .380 is very hit or miss.
You generally get two situations
1. the bullet does not expand, penetrates very deeply (potentially too much).
2. the bullet does expand, does not penetrate deeply
Neither situation is ideal.
That said, the 3.6" barrel on the PK380 is going to make it a reasonably effective cartridge if you select your ammo wisely.
The Hornady XTP (and also FTX) cartridges are known to have moderate expansion with above average reliability.
IMO, Hornady Custom or Hornady Critical defense would be two very good choices to consider.
Whichever brand of ammo you choose the most important consideration is, "Is this ammo both reliable and accurate in my weapon?"
I would - at the very minimum - recommend shooting at least a full box of self defense hollowpoints for testing.
Ideally you'd shoot somewhere between 100-200+ rounds trouble free. In my mind if I'm having trouble less than once in 200 that is an acceptable rate of failure.