eightbore, I think most any 22LRs, and particularly autoloaders can have all manner of jams. The picture in my mind is the bolt partly closed on a spent shell, sticking out of the ejection port?

Ted, just a thought, but has the edge of the chamber picked up dry firing damage. Sorry if it's already been gone over, but that could throw off cycle timing enough to affect reliability that the rifle once had. Good luck with it.