I had a front locking block issue with my p80 when I built it. I could not get the slide on at all because of the issue. I got the new front locking block in the mail yesterday and it fit in with no problems. Right as I mated the frame with the slide and tried to pull the slide back, it started binding up and would not want to go. After looking for a moment I could see that the barrel was contacting the bottom part of the slide as it was pulled back and rubbing the finish off the bottom side of the barrel. I am not sure if this is another issue with the locking block or barrel and slide. Any help could be appreciated.