That is a grail gun. We had Model 19s with 4" bbls, a few, in addition to the 2.5" bbls. many. For some reason, our armorers put some kind of butt-ugly teflon finish on the 4" guns. I have no idea why. I have always wondered what happened to the Model 19 2.5" I was issued. I guess they gave them to another agency, destroyed them or possibly a foreign country. Our revolvers were not marked to indicate the agency.