This is the Forearm tenon Winchester 1876 rifle. This part slides into a slot on the underside of the barrel and your two Forearm cap screws (wp56) screw into this and hold the Forearm cap in place. This tenon is NOT drilled OR tapped. If you have loose or new wood to fit and want to drill your own holes then use this part. If you would like a tenon that is already set screws see part number 501.