U.S. Army's use of copper in bullets cutting down on lead PICATINNY ARSENAL, N.J., July 4 (UPI) -- Nearly 2,000 tons of lead has been eliminated from production of U.S. Army small arms training ammunition since 2012. The Army's Picatinny Arsenal says lead in 5.56mm ammunition used in M4 and M16 rifles has been swapped out with copper. "The EPR [Enhanced Performance Round] replaces the lead slug with a copper slug," said Lt. Col. Phil Clark, product manager for small caliber ammunition, in the Army's Program Executive Officer Ammunition office. This makes the projectile environmentally friendly while still giving soldiers the performance capabilities they need on the battlefield. So far we have eliminated 1,994 metric tons of lead from 5.56 ammunition production. The M855A1 Enhanced Performance Round features a copper jacket and exposed hardened steel penetrator. The switch has prompted a number of significant performance enhancements over the M855A1's predecessor which was fielded in the early 1980s. According to Clark, the improvements include better hard-target penetration, more consistent performance against soft targets and significantly increased distances of these effects.