GUN-METAL. A kind of bronze ; an alloy of copper and tin which gained its name from the use of bronze for ordnance. The use of such an alloy for guns became obsolete with the manu facture of steel ordnance. Hard bronze for gun-metal was com posed of 16 parts of copper to 2 of tin. The use of gun-metal is now confined to engine parts which need considerable strength but for which steel cannot be used.