Had a sortof exciting moment during a rifle class this weekend.  One of the guys was shooting tracer, didn't know it and set the range on fire.  Had to call out the base fire dept.  We didn't realize it was tracer until the night shoot later that day, the tracers weren't lighting until 100 yds or so.  I believe he said he was shooting some IMI surplus stuff, don't remember the headstamp.  Apparently the red paint had flaked off of the tips completely.  He had to switch to his backup ammo since he couldn't figure out what was tracer and what wasn't.