[DonVoigt]

I could not get TC coated bullets to work well at all- I'd forget even trying them.

Go about the evaluation methodically, use the same ammo in each mag(good idea to number them) you have.
Start with one round in each- observe; then try 5, and finally work up to 8.

I'll bet you find differences in the performance of each mag, with each luger(different in each).

Then change ammo and repeat.

Slow and steady wins the race.

You may have to eliminate one or more mags from use, with either pistol.

I know it is maddening, but tolerances are not your friend in this case. JMHO.