This Remington manufactured late variation ejector plunger case screw is for the model 12 slide action rimfire rifle which uses the late variation ejector plunger case assembly that mounts to the back side of the trigger guard and is in very good condition with light wear.  (file photo)

Note: Remington model 12 slide action rimfire rifles with the following serial numbers have been observed with this part:

12-A: 741138 & 802984

12-C: 722004 & 789956