Well, first thing I would do is take a look at this thread on Kahr Talk:
Proper Prep Of A New Khar
I did that with both my P-380 and my PM9. I've heard people not doing this having issues. Mine have functioned flawlessly.
I sold my P-380 but when I did have it I was shooting PMC Bronze for the range and Hornaday Critical Defense for defensive. All of if cycled great and was pretty accurate at 12 yards.