Anyone else have the same problem with a Kahr PM9 that fails to lock back on the last round?

My CCW is a glock 19, but I’ve been trying to build confidence in a Kahr PM9. I purchased a new PM9 and noticed that my slide would not lock back after firing the last round. I sent in all of my mags for replacement and noticed that the same issue regularly occurs with 3/5 of the new mags.I’ve put nearly 1k rounds through the gun so far. Any idea what the cause is? Does this make it unreliable for ccw if it only happens on the last round? via /r/CCW http://ift.tt/2B1h6VJ