From: bercov@bevsun.bev.lbl.gov (John Bercovitz)
Subject: Re: watching rounds fly in

Another interesting situation wherein bullets can be observed in flight
is when the air is near 100% humidity.  Twice I've seen vapor trails
behind supersonic bullets.  Apparently the bullet's passage disturbs
the humidity into condensing into water droplets locally.  Where I've
seen this has been in shaded, damp glens.  The bullet in each case
appeared to be a high speed black bumblebee.

JHBercovitz@lbl.gov    (John Bercovitz)