I have a 308 MXLR that i bought when they first came out and i really like it. I have shot several deer with it however I started having issues with it a few years ago. after firing, the spent case sometimes stays in the chamber as though the extractor let go of the rim. i can usually correct this by putting pressure on the extractor while opening it. It may occur once every 4 or 5 shots. Is this a common problem with this gun? and how easy of a fix is it?