Iron County register. [volume] (Ironton, Iron County, Mo.) 1867-1965, 1888-11-15
STEEL GUN BARRELS.
A Novel Process by which They Can b
Made RaDldly.

| S1EEI GUN 6AHHELOs
A Novel Process by which They Can BE
Made Rapidly.
| A new process of making steel tubes
| recently developed in England threat
ems to revolutionize the manufacture
of gun barrels, at least from the small
est rifles to the rapid-firing cannon of
two or three inches bore used on war
| ships. By this process a solid bar, or
ingot of steel, is passed through set
| of rolls, and comes out tube with a
| twist fiber.
To fully understand the bearing of
| this new process it is necessary to know
how gun barrels are ordinarily made.
The rifle barrel is simply a bar of steel
rolled out to the right size by passing
it through grooved rolls. The bar is
forced into the groove and compressed
and drawn out, the grooves being of
less diameter than the ingot that is
fed in. This process makes fiber,
but the fiber runs lengthwise of the bar,
and is, therefore, less able to resist a
bursting strain from within than if the
fiber ran around the barrel But the
strength of the steel bar is great
enough to resist the strain of a rifle
cartridge, and most rifle barrels are
made by this process.
In shotguns heavier charges of
powder are used, and on account of
the size of the bore and the limit that
must be put on the weight of the two
barrels of which shot-guns are made,
thinner metal is required in the bar
rels, and therefore a tougher metal
should be used. A good many shot
gun barrels are made of plain rolled
steel. but they are not trustworthy.
To make a stronger barrel, the gun
maker piles up two ingots of the best
puddled iron and two of the best steel,
alternating the iron and the steel.
These he rolls out into rods of a rec
tangular section of perhaps three
eighths of an inch, and then twists
them into a spiral rod. Then several
of these spiral rods are again rolled
into one rectangular. The last rod
made is wound in a spiral around a
mandril, and its edges welded together
so that it forms a tube with a bore of
the size of the mandril. The mandril
is then driven out, the tube bored out
and turned down and Strengthened. 1t
is then ready to be fitted to another.
and the breech mechanism attached
so as to make a complete set
of gun barrels. Another method
is to cast the barrels of steel
nn6ar A oh
twist grain barrel is made of iron only.
The old-fashipned stubb and twist En-
glish barrel was made of old horseshoe
nails. A still cheaper twist barrel is
made by inserting one end of a square
rod of steel in an immovable block and
the other end in the end of shaft,
which, when turned by steam power,
will twist the square rod into a spiral
one. This is then bored out.
Each of these processes, except the
one producing the plain barrel with a
longitudinal fiber and the last one men
toned, require a deal of hand labor.
The aforementioned process makes a
poor fiber.
But the new process not only makes
a good fiber, but it makes one much
superior to the fiber found even in the
welded barrels, while the work is all
done by machine.
Three rolls of a canoidal shape are
so placed that a rod or ingot may be
fed lengthwise between them. One
end of each roll being larger than the
other, it follows that the surface of the
big end of a roll travels faster than the
surface at the small end. When, there
fore, bar of steel in a plastic state
is fed in at the smaller ends of the
rolls, it is not only whirled
around, but the forward end
is whirled with increasing speed.
The forward end is drawn with
increasing speed as well as twisted
around. The surfaces of the canoidal
rolls being parallel with each other,
there is no decrease in the circumfer-
ence of the bar, and so it happens that
the metal needed for the increasing
length of bar is drawn from the axis.
1t is as if bar of plastic metal were
whirled on its axis until the centrifugal
force caused it to expand into a larger
bar with hole for an axis.
In active practice a mandril is driven
into the opening tube as the bar is
whirled into the shape of a tube. The
mandril is used not to make the hole.
but to perfect it. The tube thus formed
is not only the best, but it is just about
as cheap as any for gun barrels.
The process has been partly under
stood for some time, but iron masters
of experience doubt ID its practical de-
velopment, so that it was not adopted
in practice by any one until within a
few months. The result of the new
process is sure to be the lowering of
the cost, and probably the price, of
first-class guns, as well as those of
other grades.-M Y. San.
A ROYAL OCULIST.