I've cleaned and oiled it thouroughly, actually been shot very little. This is the Sears m-200, 3" chamber. Load normally and now cannot extract live shell or hull. Extractor engaging as it will tear brass if butt slammed down. Chamber clean and shell drops in and out of barrel easily with barrel removed. Something is holding shell in chamber but danged if I can figure it out. Ejector pinned in place as it should be. Any ideas? Thanks.