dannyelle is right-on about the double recoil spring. There is a lot "going on" there when the cartridge fires and the spring(s) go into action. Maybe, I have been extremely lucky with my five kahrs (CW380, PM9, PM40, P45 & TP45), as I have only had one instance with a few repeated FTEs and FTGBs. These were all with the PM40. Those who have shot the PM40 know that this is a snappy little pistol. In my opinion, the PM40 is very reactive to even a hint of limp wristing. I was fairly sure I did not limp wrist my PM40 when it had the hiccups.

I searched this forum and the other Kahr forum. I believe it was this forum I found the solution. It was the double coil recoil spring. Someone had the same problem with a model that has the double recoil spring setup. He found that the double springs in his Kahr were binding and hanging-up occasionally on the guide rods. This normally smoothes out as rounds fired increases. But you can hurry it along. He took some type of multi-purpose EP grease and thinly coated both guide rods. It worked for him. I used Lucas Red "N" Tacky #2 and thinly coated both guide rods. Hand racked the slide about a hundred times and went to the range. Over a period of two days I shot 150 rounds and experienced zero problems or issues. This may not work for you. All I can say is this little PM40 is now one of my favorite Kahrs and is in every day carry rotation with my PM9. Good luck with your Kahr(s). I hope they will smoothe out for you.