The Manitowoc pilot. [volume] (Manitowoc, Wis.) 1859-1932, 1859-08-19

1t is universal fact that every missile,
whether forcibly projected from gun-bar-
rel, or in any other manner impelled thro'
the air, is partially arrested by the power
of gravity and by an atmospheric resist
ance. The first of these causes operates
in lowering the time of flight, the second
diminisbes its speed, and the two together
generate the curved line which constitutes
the path Of the bullets Besides this, how
ever, every cast bullet has certain irregu-
larities on its surface, and in its internal
structure, Of themselves sufficient, through
the resistance of the air, to make it deyiate
from the line of aim. The rifle grooves,
if properly cut, give the bullet rotary
motion upon It's axis, and maintain that
axis, coincident with its line of flight
Each irregularity, therefore, in its struc-
ture is by this means presented in regular
succession to the action of gravity and Of
the air during its entire course.
Every rifle bullet has these two distinct
motions-a forward motion given by the
explosion Of the powder, and spinning
motion impaired by the spiral grooves
through which it has passed. The force Of
gravity will act upon it in proportion to its
diameter and to the square of its velocity
The grooves Of the rifle should only, there.
fore, have such a twist as will set the bull
let spinning on its axis, without too great
ly increasing its friction against the side OF
the barrel. If the twist be too great, ii
will not only do this, but will cause the
ball, during its flight, to offer its various
irregularities too rapidly on the action o.
gravity and of the air. 1t has been found
that, at two hundred and twenty yards, a
rifle, ninety guage, the barrel ninety five
diameters long, and projecting flattened
conical bullet weighing one hundred and
forty grains, with sixty grains of powder,
of moderate strength, and with a gaining
or increasing twist, ending at one turn at
forty two inches, will send its bullet with
less variation in side wind than any 9TH
er combination Of calibre and twist.
To produce the greatest effect at four
hundred and forty yards, the calibre should
be eighty to the pound, the twist ending
at one turn in thirty nine inches; and for
a range of six hundred and sixty yards a
calibre of seventy to the pound will be re.
quisite, with a twist ending at one turn in
thirty six inches. For very great distance
heavy bullet becomes indispensable, be
cause 1.-TWO bodies of different sizes, but of
equal density, be supposed to be moving
through the air, and starting with the
same velocity, the smaller will lose its
momentum sooner than the larger. A six
ty or ninety guage rifle may perform admi-
rably up to three hundred yards, but at
ranges of seven hundred, eight hundred,
or one thousand, it would not for mo-
ment compete with one carrying one and
three-fourth ounce ball, unless the bullet
were formed upon the well-known Lancas-
ter pattern, whereby not only is all wind
age disposed with, but minimum surface
is opposed to the air, and the projectile
becomes, in part a short blunt leaden ar
row, or bolt. In perfectly calm atmos-
pheIe, bullets ofninety guage may make a
good practice at a somewhat long range,
but even light breeze will be sufficient to
sweep them out of their proper COURSE
the reason being simply that the momen-
tum Of a small bullet diminisnes so rapidly
rs to render it incapable of maintaining its
proper line of flight.