I was given 40 rds of old military ammo from a friend at work. 20 rds are tracers, 20 are regular FMJ. Most of the headstamps are marked LC 42 or EW 43. From what I have found this means Lake City ordnance plant and au Claire Ordnance Plant and I assume the numbers refer to the year. They are in their original boxes. Is this stuff safe to shoot? Would it be better to keep it as a collectors item? Thanks!