I had a very similar problem with mine. It would jam and it would put a mark in my brass about 1/8" from the base of the brass where it was hitting. I called Marlin and they had me send the rifle in. I complained of the action not being very smooth, the jamming, and brass being marked when attempting to chamber. Marlin replaced the barrel, lever, carrier assembly, and did a full action job on the rifle. It came back as slick as any lever rifle I've ever experienced. The accuracy was much improved upon return, too. The turn around time was right at three weeks, but it was vacation time for them. Further, Marlin will reimburse your shipping expenses, if you request it.