These models have been known to be ammo-sensitive: What works in yours may not work well in mine, and what works in mine may not work well in yours. The best advice might well be to take your pistol out to a local range and run a variety of ammo through it from a variety of manufacturers, noting the operation of the pistol during each experiment. Then simply select the ammo that works best, time and time again, in your PPK. It can be a bit on the expensive side, but we are talking about life, after all.
Welcome to the forum, by the way. Enjoy your time here.
Welcome to the forum, by the way. Enjoy your time here.