This Thompson Center manufactured late variation forward upper tang / trigger guard screw is for the late variation Hawken muzzle loading rifle which has the hole completely through the stock and allows this screw to secure the tang tight to the stock and pulls the trigger guard tight up into the stock. Your muzzle loader requires the third variation stock and third variation trigger guard. This screw is in very good condition with light wear.  (file photo)

Note: Thompson Center Hawken muzzle loading rifles with the following serial numbers have been observed with this part:

Percussion: 489495

Flintlock: