See my thread on "Are Kahr's junk?..."
Two of the three local dealers told me the new Kahr's are poorly manufactured. He did say the older ones were made better, and the 9mm's had some loading issues with certain types of HP ammo. And, he said the .40's didn't seem to have problems.
Some of what you are seeing may just be break-in issues. Everyone has told me you need to get through 200 rounds to break it in.
Interested to hear the outcome...I have a used PM9 on the way.