Check that the ejector is installed correctly. The little round nub needs to be in the hole in the left side of the receiver.
DING DING DING DING!Widowmaker said:The Marlin has 2 small screws that are similar in size the go in the bottom of the receiver and left side. The longer of those screws goes in the bottom, the shorter one goes in the left side.
Right now, thats all I can think of.
..........Widder