My sister in law is recently getting into the world of firearms. She purchased a marlin model 60 from a pawn store. The problem is if left to its own mechanics it will slam the round to the right of the barrel, almost like a stove pipe but for a live round being fed. If I slow the action down manually the live round starts the feed process normally grabbing the round and begins to push the round forward. About halfway to the ramp (couple mm) the round is thrown from the gun to the floor. Any ideas?