Hello. I have searched the forums but was unable to find the answer to my problem. I have 590 Mossberg, a police trade in, which sometimes fails to grab and eject spent shells. I had that problem repeatedly this past weekend (even after just a couple shots) when shooting field loads with aluminum bases - the shell would stay in the barrel requiring a knife to extract. The chamber is smooth. When I removed the bolt, which was clean prior to using, it seems that the spring on one of the extractors is relatively weak. I have been looking for instructions on disassembling the bolt and replacing the springs. It looks like there is a pin that can be knocked out, but I would like to see what I am getting into before I get into it. Any help would be appreciated.