This Harrington & Richardson manufactured rear sight mounting screw - thin head variation is for the model 865 Plainsman bolt action rimfire rifle and is in good condition with light slot wear. The head on this screw is thinner than the standard screw but the threads are the same. (file photo)

Note: Harrington & Richardson model 865 bolt action rimfire rifles with the following serial numbers have been observed with this part: AX570318