I'll preface this by saying that I have had problems with the only Kahr pistol I ever purchased, a CW9. I still loved the gun for all of the reasons i initially purchased it and am more than willing to try again but want to be a little more informed this go-round. A local shop has 2 used Kahr .40cal pistols. One is a CW40 ($350 w/<100rds fired) and the other a PM40 ($499 unknown age). I know that the PM40's had some early growing pains. Can anyone tell me what to specifically look for on one of the early PM's and what date range or serial number range would be considered the "updated" PM40? I can usually talk them down another 10% on used guns so I think I could potentially end up with a great gun at a great price if I play my cards right. Thoughts? insights? cautions? experiences? ever been to a Turkish prison?