This 500 pound-class 3” rifle is a rarity, with few survivors of its type known. The top of the tube is marked “3”/Rifle/500lbs/No.8/anchor proof” between trunnions, and according to the serial number, was deployed on the USS Brooklyn. The breech is marked “ORD.DEP.U.S.N.Y.Washington”. The brass elevation screw on the carriage is U.S.N.Y. inspected and dated 1878.