Here's the direct link to Sieger's load data post (referenced above):
http://forum.lugerforum.com/showthread.php?t=31849
I have also used Hodgon TiteGroup powder (3.8gn) with 125gn Truncated Lead Conical Nose Lead bullets to good effect.
Their load data for a variety of bullets and their powders (if I could only find some locally) is at:
http://data.hodgdon.com/cartridge_load.asp
Finally, I'll assume that you've maintained and cleaned your Luger prior to sessions with the ammo you're having difficulty with, and that the pistol has adequate handhold support during firing. Both of these things can interfere with proper Luger cycling with any ammo.
Marc
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Igitur si vis pacem, para bellum -
- Therefore if you want peace, prepare for war.