Metal alloys of 90 or 95 percent copper and the remainder zinc. Also termed Commercial Bronze. Neither name is recommended by Copper Development Association, Inc., but instead Alloy No. 220 and Alloy No. 210, respectively, are recommended. Used extensively for the manufacture of bullet jackets.

a brass that is rich in copper; used to make articles that were to be gilded

A copper-zinc alloy used for bullet jackets, consisting of 5 parts zinc and 95 parts copper. Commercial bronze (10 parts zinc to 90 parts copper) is informally referred to as gilding metal when used for bullet jackets.