Bullet Lead-Manufacturing Process
Lead used in the bullet-manufacturing process is generally obtained from secondary lead smelters where the raw material is made primarily of recycled automobile batteries. Under stringent environmental regulations, these smelters separate the batteries into plastic, acid, and lead components. This lead is then mixed with lead from other sources and melted in kettles with capacities of 75 to 100 tons. This scrap lead is reprocessed into ingots (also called pigs). Elements such as copper and tin may be present but are controlled within limits determined by the economics of the process and use of the product. For bullet manufacture, there are few physical requirements for the lead. Chiefly, the lead must be processable. Antimony may be added to harden the alloy, but its level will also vary with the requirements of the product and the economics of its use. Hardened lead is generally used in non-jacketed bullets, whereas soft lead (i.e., lead where antimony has not been added) is generally used in jacketed bullets. The other elements are present in trace amounts and can vary.