I have tried +P and Double Tap in My PPK/S and could never go through a magazine without a failure to feed. They did not "feel right" upon discharge in the pistol either. I have never had any problems with standard pressure ammo in either hollow point or full jacket. I do not know why, I just know that the higher tuned loads do not work in my Walther. I suspect the blow-back design may have something to do with it but in any event, it was a mismatch. I hope this helps.