-=> Quoting Nermal to John Sandow on 06-09-96  13:01 <=-
 Re: more falling bullets
 Ne> Hatcher's notebook devotes an entire chapter to this subject.  Bullets
 Ne> fired from '03 Springfields straight up did not fall fast enough to
 Ne> penetrate a tin bucket nor the tin roof of the shanty structure Hatcher
 Ne> and Co. were in. One bullet struck a pine board in a boat used for the
 Ne> tests and penetrated 1/16 inch before bouncing into the water.  The
 Ne> return velocities were calculated at about 300 fps.  30 ft lbs given a
 Ne> 150 grain bullet.  While these could concievably be lethal this would
 Ne> be very unlikely.  The military considered bullets returning from
 Ne> extreme altitude to be non-lethal. This says nothing of bullets which
 Ne> are not traveling straight up-straight down.  Every year it seems
 Ne> someone is killed or wounded from July 4 cowboys firing their guns into
 Ne> the air.  It is the horizontal velocity in these cases which makes the
 Ne> bullets potentially lethal.
Well, not quite ...
A study found in an old issue of the American Rifleman (sorry, forget the
year) indicate there are 3 possibilities. If a bullet is fired straight
up and without a crosswind, it'll fall base first. Now, on a boattail
this may still be fairly efficient and thus do a fair amount of damage.
What keeps it from tipping over? Angular momentum (spin)!
Of course, that means that if you fire it at enough of an angle (so that
the bullet still had a decent horizontal motion when it reached its
apex), it would fall point-first. In the study mentioned, a bullet
falling point first impacted with about twice the velocity of one falling
base first (but that would depend on the relative BC, of course). It
doesn't have to have any horizontal velocity remaining by the time it
hits the ground, though.
The third possibility lies between the first two. If the angle is not
steep enough for the bullet to fall base first but too steep for it to
fall point first, it'll tumble on the way down. This is the least
efficient way for a bullet to fall, and in the quoted study it ended up
with a velocity about half that of the base-first case, or 1/4 of the
point-first case.
Naturally, a heavier or more efficient bullet will have an even higher
velocity when it impacts, so that a .50 might even be fatal base-first
(if it impacts the right area).
I think that even in the point-first case, there is only a small area
where a vertically-falling bullet could be fatal. The only vital area
would be the skull, unless you were lying down, and the skull is
moderately hard.
Steve
... If at first you don't succeed... RELOAD!
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