Problem is the chamber is too large in diameter.
I made chamber casts of the PPK-S 380 Auto and my SMC 380 Hungarian.
The SMC 380 measured .378" diameter and the PPK-S measured .384" diameter. That puts the PPK-S a full .006" larger than the SMC making obvious the reason the PPK-S bulges and splits brass and the SMC fired brass is and looks normal.
Now for some troubling information. SAAMI Standards for Cartridges and Chambers has the 380 Auto chamber diameter at .3809" plus .004" minus 0.00". That would mean the PPK-S is near the high limit and may be considered within specifications.
I consider the PPK-S to have a junk barrel that ruins brass, splits many and this results in poor accuracy.
I will be talking to S&W tomorrow to see if they consider this barrel within specifications or not and if they can replace the barrel with one more like the chamber in the SMC 380.
I did run two magazines of new factory ammo through the PPK-S by hand cycling the slide and found no scratch marks on the shell casing.