ut take it
into the field; and if you distrust yourself, get some one in whom you
have confidence to try it for you. Choose a perfectly calm day. Have a
rest prepared on which not only the gun may be laid, but a support may
also be had for the elbows, the shooter being seated. By this means, and
with the aid of globe- and peek-sights, (which should always be used in
trying a gun,) it may as certainly be held in the same position at every
shot as if it were clamped in a machine. For your target take a sheet of
cartridge-paper and draw on it a circle of a foot, and, inside of that,
another of four inches in diameter. Paint the space between the rings
black, and you will then have a black ring four inches wide surrounding
a white four-inch bull's-eye, against which your globe-sight will be
much more distinctly seen than if it were black. Place the target so
that when shooting you may have the sun on your back. On a very bright
day, brown paper is better for a target than white. Begin shooting
at one hundred yards and fire ten shots, with an exact aim at the
bull's-eye, wiping out the gun after each shot. Do not look to see where
you hit, till you have fired your string of ten shots; for, if you
do, you will be tempted to alter your aim and make allowance for the
variation, whereas your object now is not to hit the bull's-eye, but to
prove the shooting of the gun; and if you find, when you get through,
that all the shots are close together, you may be sure the gun shoots
well, though they may be at considerable distance from the bull's-eye.
That would only prove that the line of sight was not coincident with the
line of fire, which can be easily rectified by moving the forward sight
to the right or left, according as the variation was on the one side
or the other. Having fired your string of ten shots, take a pair of
dividers, and, with a radius equal to half the distance between the two
hits most distant from each other, describe a circle cutting through the
centre of each of those hits. From the centre of this circle measure the
distance to each of the hits, add these distances together and divide
the sum by ten, and you have the average variation, which ought not to
be over two inches at the utmost, and if the gun is what it ought to be,
and fired by a good marksman, would probably be much less. This is a
sufficient test of the precision for that distance, and the same method
may be adopted for longer ranges. But if the gu