Atlanta tri-weekly journal. [volume] (Atlanta, Ga.) 1920-19??, 1924-11-08
Gun TESTS SHOW
BULLET TRAVELS
FASTER THAN SOUND
RY FREDERIC J. HASKIN

BY FREDERIC j. HASKIN
WASHINGTON, ID. c., Nov. TT
a man is shot and instantly killed by
a bullet from heavy automatic re-
volver in a room of average size
does he heard the noise made by the
discharge of the weapon? Or if he
is shot and instantly killed at long
range-say half a mile-by a bullet
from a high power rifle, does he hear
the noise of the gun?
Obviously the victim in either
ease never will furnish the testi-
mony that might be accepted as con-
elusive, or at least he will be unable
to do so until more efficient COM
munication is established with the
spirit world. However, experts in
ballistics assert unhesitatingly that
the answer to each question is a
negative-in both instances the bull
let travels faster than the sound OF
the gun that projected it.
This is determined by a simple
calculation, for sound travels at the
rate of LOO feet per second, while
the speed Of a bullet is appreciably
faster for the first 5000 feet or SO
of it's range. How much faster va
|ries according to the initial velocity.
the explosive charge, and other fac
tors, but it is said that the bullet
from any high-power rifle will beat
the sound Of the gun for distances
up to three-fifths of mile.
Beyond that the bullet slows down
until the sound of the gun catches
up with it and then outstrips it,
which means ranges at which the
victim might hear the crack of the
rifle that kills him.
Hero Feels Sting First
However, it seems that few fiction
writer's are experts in exterior bal
listics, for when they tell of the
shooting of their characters they al
most invariably have the sound of
the gun preceding the impact of the
bullet, even at comparatively close
ranges where this would be utterly
impossible. How often dc we read
that the hero "heard the sharp crack
of rifle and the next instant felt d
singing sensation in his shoulder"
or heard the crash of the automatic
and the next instant consciousness
was obliterated," or some such eX-
pressions?
Does Bullet Hiss Or Sing?
They are all wrong about that,
lust as most of them are that de-
pict the sound bullet makes in it's
flight. According to the authors of
the stirring tales that feature shoot
ing, a moving bullet makes almost
every conceivable sound. Inspection
of a dozen such stories is said to
have revealed the surprising ver'
satility Of a bullet in that it is varl-
ously described as singing, kissing,
cumming, whining, droning, howl
ing, shrieking, whistling, crashing,
whispering, bazzing, and what not
Just what kind of a noise a
speeding bullet does make is told by
Captain E. c. Crossman in an ar
ticle in Cutters Recreation. He says
that it is sharp crack, somewhat
like that of an effectively manipu-
lated bull.whip.
Battlefield observation is not, as
rule, very reliable, according to
this authority, but bullet does nor
change it's sound because of being
used in battle, and, therefore, if bat
tlefield conditions as to range are
duplicated, with the addition of en-
tire knowledge of missile, distance
and other factors, it is possible to
make accurate observations and ar
rive at sound conclusions.
'Our work at the army small
arms ballistic station in which keen
observation at the receiving end of
the bullet flight was as important
as intelligent Gun-laying at the fir
ing end" says Captain Crossman,
permitting much data as to bullet
noise at the various ranges.
about the most definite proof
that most of our fiction gentlemen
get their firearms knowledge from
reading other fiction, or possibly
from cursory talks with gan store
clerks, is the fact that not one Of
them ever mentions the most char
acteristic sound of the modern bull
let. The man who has had a long
blacksnake whip cracked violently
three feet from his ears would
never describe the sound as a hum
or a whisper nor yet howl.
Vacuum Causes Cracking Noise
Modern cartridges drive their
bullets fast enough to create q par
tial vacuum at the base, and the
air, rushing in. makes a sharp
crack, most nearly described by the
vicious cracking of long and we'll.
handled whip
Experiments at Miami
One of the most Illustrative exam
pies of this noise, explains the cap
tain, lay in the erosion firing done
at Miami to determine the life of ma
chine-gun barrels with various types
of powder. The gun was laid to drop
the bullets into the water at the
. ,000-meter mark, one and quarter
miles from the gun, and in front of
the observation tower. Sitting on
the upper platform Of the tower the
officers observing could watch the
strike of the burst, estimate its
length, and accurately tell when the
machine gun barrel was wearing out.
The firing of the gun was always
first announced, the observers found,
by a sharp rattle in. the receiver of
the field telephone set on the plat
form with them, sounding much as
if someone were ringing in on the
line.
The next announcement of the
coming of the bullets was a thin,
sharp cracking noise from the air
between the observers and the gun
following the first rattle in the tele-
phone with an interval af about 5
seconds. Almost on the heels of the
first of the cracking noises came
the bullets, with their thudding
splashes into the water fifty yards