The Glasgow courier., 1916-02-11
BULLETS IN FLIGHT
Even the Best Aimed Ones Never
Follow Their Noses.
STRIKE A WEE BIT SIDEWAYS,

OSSVNe ~ Wilt W 0uOCvVAU y,
The ProjectiIe Travels on . Curve, o.
Course, and Il Keeps its Axis Always
In the Direction the Axis Had When
the Ball Left the Gun.
1t Is u we'll known fact that bullet
never goes straight to a mark. but flies
in Il curve on the order of the parabola.
But most people think that the bullet
itself follows its nose and that at first
when the nose is pointed up) the bul.
let follows It and that when the bullet
is coming down on the other leg of the
curve the nose Is pointed down.
This is mistake, for the nose Of q
bullet always maintains its own direc.
ton, no matter what the bullet as a
whole tries to do. That is. IL a gun be
pointed slightly up, the bullet. when 1t
strikes the target, will not enter 1t per.
pendicularly by the nose. and the hole
made will be larger than the bullet is
round. for the bullet Of necessity must
hit in certain degree aatwise. OF
course the reason the bullet does this
Is because It has a very rapid rotation
given It by the rifles in the barrel,
which keeps It also from turning over
and over in the air.
Another thing that will seem peculiar
to most people is the action Of gravity
on a bullet. II a gun be fred exactly
horizontally the bullet will have to be
pulled down by gravity exactly sixteen
feet during the first second. So il there
were no sights on gun and it was
leveled by means Of a hand level and
fired the bullet would hit something
exactly sixteen feet below the gun at q
distance away equal to the velocity of
the bullet per second.
No matter what the bullets velocity,
gravity will pull it down sixteen feet
during the first second. or If the bullet
be fred upward gravity will take from
its upward velocity thirty-two feet dur
ing the first second.
The bullet itself keeps its axis al
ways in the direction the axis had
when the bullet issued from the gun
This is the we'll known gyroscopic prin
ciple made use Of in the gyroscopic
compass and the monorail car-that a
rotating body will maintain it's axis Of
rotation III the same direction unless a
moment Of force be applied to It.
But what actually happens with the
modern high powered rife? Does it
shoot bullet that goes in sideways?
To slight extent it may he stated
that the modern army bullet does do
that very thing. Its velocity. however.
is so enormous that the gun barrel does
not have to be elevated through SO
large an angle, and consequently the
bullet enters fairly on its nose, though
not squarely so. ut all ordinary ranges
The same may be said Of the bigger
guns. They have riding in them and
so give rotation and gyroscopic action
to the projectiles. But mortar does
not. 4 mortar shoots something al,
most straight up in the air and let's it
fall down AS the mortar is too shor,
barreIed to be rif1ed the top OF the pro
jectile would hit Il target long dis
tance away. but for shot almost
straight up in the air to fall right down
of course the bottom Of the projectile
would strike first. The mortar projec.
tiles are generally round. so that 1t will
not matter how they strike.
The reason bullet cannot be made
so that it will always enter target
squarely on its nose is that for every
range Il differently shaped bullet would
have to be manufactured: also the bul
let should he symmetrical. 50 that the
air will exert no disturbing influence
on its distorted parts.
A bullet has Il distinct curve like that
Of Il baseball. due to Its rotation. and
this curve Is independent of the parab
ola given by gravity The smoother
and more polished Il bullet is the less
is this curve. But the action Of the
riding in gun barrel puts little
grooves in the bullet ns 1t goes through
the barrel. These catch the air as the
bullet rotates and causes the curve
spoken Of
II the bullet lie rotated in the dlrec
ti0n OF the hands OF n clock the curry.
will make the bullet so to the left OF
the exact point aimed at. The effect /.
so small. however. that It does no,
have to be taken into account in the
manufacture Of rifles and ammunition
New York American.