I bought a Kahr PM40 about a month and a half ago. I put 100rounds through it and nearly ever mag the slide would lock back. I made sure it wasn't my grip. One of the employees of the gun store even put two mags through it. He said it locked back on him twice. So they said the'd send it back to Kahr and it would be back in 1 week.
Well a month goes buy and I call Kahr with the serial #. They say they never got the gun. I made a few more calls over the next two days and finally got it tracked down. Now a month and a week later its back in my hands. Kahr changed the slide stop, recoil spring, guide rod assembly, and two new mags. I put 100 rounds though it today and it was 100%. No malfunctions what so ever. I'll put 150 more rounds of fmj through it and if its still 100% I'll keep it.
Hopefully it will stay 100% because this little gun packs a lot of firepower into a very small package. It's not the most accurate gun I own but it will do the job. I can't expect too much from a DAO 3" 40 cal. Only downside of this gun is that extended range time can leave you a little sore. But I find the PM40 much more controllable and pleasant than the Airweight S&W 38 I rented.