This is the screw (long) that goes into the magazine plug on the Winchester 1866, 1873, 1892, 1894 lever action rifles, and model 53. This screw goes all the way through the plug and magazine Forearm and fits into a little hole on the bottom of the barrel to secure the magazine. Overall lenght of the screw is 0.725 inch. If you do not have a hole on the bottom of the barrel screw to fit in to then you want to use the SHORT plug screw, part number wp64b. NOTE If you have a model 1886 that uses the mag plug with NO LIP, uses the long plug screw part number 713B.