Is the ammo safe in a blowback? 65 grains at 1300 feet per second sounds awfully hot to me. I would look for videos of PPK pistols firing the ammo before I volunteered as a product tester.
Assuming the ammo is safe, the next question is will it work properly. The PP series is finicky about ammo. This is especially true of the 380. For example, none of my 380 Walthers will work with Winchester white box - a flat nosed bullet. It nose dives into the feed ramp because it is too short. Others here have had no problems with this same load. If the gun is to be used for carry, it must be one hundred percent reliable with the chosen ammo. I generally fire 200 rounds of the chosen rounds through a pistol I am going to carry.
Assuming the ammo is safe, the next question is will it work properly. The PP series is finicky about ammo. This is especially true of the 380. For example, none of my 380 Walthers will work with Winchester white box - a flat nosed bullet. It nose dives into the feed ramp because it is too short. Others here have had no problems with this same load. If the gun is to be used for carry, it must be one hundred percent reliable with the chosen ammo. I generally fire 200 rounds of the chosen rounds through a pistol I am going to carry.