ammo for 7.65/.320 pp/ppk

Hi, I have a Walther PP made in France in 1955. The barrel says 7.65mm. I have .380 cartridges and they keep jamming. Am I supposed to be using .32 caliber? Any advice is appreciated. Thanks, Jason

I recently purchased a post-war PP, 7.65mm and am looking for suggestions for ammo other than FMJ rounds. Anyone find something that works well in this gun? I've seen a fair number of reports that hollow points and JHPs rounds jam in this gun as well as other suggesting that a few mfgs have...