I just got this CZ52 and shot it today. and after the last shot for the mag ,I noticed the slide was not locking back. I have two mags So i used both of them , One of them , the slide once in awhile wold lock back. I shot around 250 rds thru it. I had no jams and no misfires, the gun is excellent, except for the slide not locking back all the time when the last shot is fired. Anyone have any ideas, how to fix this , i would definitely appreciate it.... Thank Mac