Ok i got into an argument about the feasibility of this idea. For every bullet ever made from now on, put a metal composition inside of it that is unique to every single bullet produced. 0.09864 moles/g MgS 0.00787 moles/g Ca2S 0.01535 moles/g Cu4Zn3 0.06772 moles/g Ti5Cd2 Bullet cases sold at Wal-Mart in Charleston, West Virginia to Richard Hammonds on 9/12/06. Was the example "ID". Is this at all possible? Also what was included in the argument is how this would stand up in the real world after being actually fired from a barrel and after hitting a target. Also, for anyoen who has an answer... what are your credentials if ya dont mind.