I've been pocket carrying (in an appropriate holster) my 642 for the hot weather months. I had my hand in my pocket and felt the cylinder latch bolt (nomenclature?) with my thumb. The hollow nut that attaches the release latch had done a runner somewhere in my pocket. I found it and the latch later and tightened up the whole business. I've been carrying revolvers since 1975 when I carried a model 10 in a duty holster. This is the first time that has happened. Posted more as a caveat for others (and myself) that an occasional inspection of these parts is a good idea. I appreciate that the 5 shots on hand would not have been affected, bu will check this going forward when I carry the 642.