The Dickinson press., 1913-07-19

MODERN AUToLoApINe RIFF lie.
The machines for drilling and boring
are the best that money car buy and
the operatives the most skillful to be
found anywhere. Care at this stage
reduces the necessity for Strengthening
later. Every point is given the minut.
est attention. In drilling e cclibers,
for example. the length of the hole
must be from 100 to 125 times the 81.
ameter of the drill.
Taking OF 2 1000 Of an Inch.
The boring is an especially delicate
task. In chokeboring your shotgun.
for example, the final reamer took OF
only 2-1OOO Of IN inch. Think of such
a gossamer thread Of metal! But it in.
sures accuracy.
Looking at Reflected Lines.
But here is the inspection depart,
ment. Hanging In the windows are
translucent frames with a black line
across the center of each. You will
see n of the inspectors take a barrel
from the waiting rack, hold n end
toward the light, squirt critically
through the tube and lay it aside ap-
provingly.
You pick it up and follow his exam
pie. First you point it straight at the
black cross line on the frame. Then
you tip up the farther end ever so lit
tie and see how two reflected shade
lines form on the shining inner surface
and run down the barrel toward your
eye. These lines are straight as a die;
therefore the barrel is perfect. Should
either one waver the slightest fraction
the inspectors quick eye at once de.
tects it.
There are 24O inspection points and
b17 gauges must be used-forty-nine
on the guard, forty-six on the receiver,
thirty on the breech block, and 80 on.
On the receiver for the No. 10 repeat
ing shotgun, however, seventy gauges
are used, and thirty-one for the tri2-
ger alone.
Beyond the Power Of Sight.
Some Of these gauges are marvels Of
delicacy, but there is one machine used
| which perhaps has never been equalcd.
Not only will 1t make measurements
to n twenty-thousandth Of an inch,
but it is actually sensitive to differ
ences of a ONE HUNDRED THOU
sANDTH OF AN INCH. Such a mi
mute dimension we cannot even
imagine. 1t is beyond the range Of the
most powerful microscope, and yet
here is q piece Of mechanism which
can really detect it !
Testing With Loads.
First, then, is the barrel as perfect as
we believe 1t? We know that it IL
perfect in gauge and. workmanship,
but Is there the slightest chance Of an
invisible flaw in material? The origi-
nal tests Of material made this very.
very unlikely, but we will take no
chances. If there be such a flaw it
must burst at more than double the
service charge.
Accordingly the gun is laid in a rest
opening in the wall into a bank Of
sand. We get behind a steel plate for
safety and put cotton in our ears. The
trigger is pulled by means Of a string.
Bang! The gun is uninjured. Its
strength has been assured
Then follow tests for action and
speed, and If the gun be an auto load
er the swift rattle OF tts discharges IL
surprising. The well gagged parts
move as smoothly as the works Of a
watch. And finally there are the tar
get tests.
Firing ut Targets.
Rife after rife in succession Is laid
in q rest and fred at a mathemadcally
divided target upon the hillside.
The results are noted through q tele-
scope. Difficulty at this point invaria-
bly, rejects the rifle.
Shotguns are discharged at paper tar
gets in the shooting gallery. We walk
through the hallway that runs outside
to the point where a boy is handling
the targets. We hear a distant bang.
The boy pulls a handle In the side Of
the wall and a frame energies bearing
a well peppered sheet Of paper. This
he unfastens and hangs up for refer
ence, pinning a fresh sheet in its place.
These targets must all be examined
and every shot hole be counted. II in
any Ease there be found less than Is
per cent of the shot within q circle Of
thirty inches from the center the gun
is at once rejected.
Here we find, a long way from the
cave man, thousands Of skilled me-
chanics producing arms and ammuni-
ton very different from the thrown
missile Of the stone age. And the part
played in the wars Of the earth has
given way largely to the serving Of
peaceful hunters and marksmen.