Hello Noel,
In Harry Jones' book, Luger Variations on pages 29-30; he describes in detail the variations amongst recoil springs of many different new model lugers (having sampled over 100 guns). He does not seem to differentiate between .30 cal. and 9 mm.; but this book was written long ago...
Look forward to your findings...
Regards,
Pete... <img src="graemlins/yltype.gif" border="0" alt="[typing]" />