[sci.military] Falling Bullets

HORN%HYDRA%sdi.polaroid.com@RELAY.CS.NET (01/11/90)

From: HORN%HYDRA%sdi.polaroid.com@RELAY.CS.NET
There were some firing range tests made with shots in the air.  I have
to do this from memory because my copy of the report is in storage.
I believe it was Aberdeen that made the attempt.  They were unable
to get any measurements because they were unable to compensate for
the wind drift well enough to find the bullets when they fell.  This
does place an upper bound on the speed in that the bullets did not raise
enough dust to be located.  Since it was a rather pointless test, they
just gave up.

The terminal velocity will depend on two major factors:  the bullet 
size and weight, and whether it is tumbling.  If you avoid tumble, then
terminal velocity should be above 50 m/s and below 400 m/s.  Depending
upon the  bullet and where it hits these speeds are high enough to cause
injury, but few injuries will be serious.  If the bullet has tumbled, the
speeds drop a lot.

The real danger is from the sloppy definition people use of ``in the air''.
In a NY case, some years ago, the ``in the air'' turned out to be at
20 degrees above horizontal and normal bullet drop brought it back down
before the speed had dropped below dangerous levels.

Rob Horn           horn%hydra@polaroid.com