stove pipe jam

[Lugerdoc]

Generally, the WW2 Mauser PO8 have a 22 turn (vise 19 on WW1 9mms) recoil spring, to enable them to use the same ammo as the 9mm SMGs. So you could try some +P ammo to see if that improves your function, but more likely either your ejector is sticking in the receiver or your extractor is worn or needs a new spring. TH