The Lebanon express. (Lebanon, Linn County, Or.) 1887-1898, 1888-12-28


ass 81 making steel tubes /
~sSsitly developed in England threat-
ems to revolutlonlae tho manufacture
of gun barrels. at least from the small
est rifles 70 the rapid-irlng cannon Of |
two or three inches bore used on war;
ahIps. By this process solid bar. or
Ing0t OF STEEL Ia passed through set |
or rolls. and comes out tube with u
twist fiber
10 fully understand the bearing OF
this new process il Is necessary TO know
how gun barrels are ordinarily made.
The rifle barrel In simply bar of steel
rolled out TO the right size by passing
&c through grooved rolls. The bar Is
forced into the groove aud compressed
and drawn out. the grooves being OF
less diameter than the ingot that 10
fed in. This process makes q fiber.
bat the fiber runs lengthwise OF the bar,
and Is. therefore. less able to resist a
bursting strain from within than II the
kiber ran around the barrel. But the
strength OF the steel bar IL great
enough % resist the strain OF rifle
cartridge, and most rife barrels are
made by this process
In shotguna 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 q tougher metal
should be used. A good many shot
gun barrels are made of plain relied
steel. but they are not trustworthy.
To make a stronger barrel. the gum
maker piles up two ingots of the best
puddkad iron and two of tha best steel,
alternating the iron aud the steel.
These he rolls out into rods OF rec
tAagalar section of perhaps three
eiRhths Of an inch. and then twists
them into q spiral rod. Then several
or these spiral rods are again rolled
into one rectangular. The last rod
made IL wound in a spiral around a
mandrii. and It's edges welded together
90 that it forms tube with bore OF
the size OF the mandril. The mandril
is then driven out, the tube bored out
and turned down and Strengthened. II
e then ready TO be fitted TO another.
and the breech mechanism attached
30 as 10 make q complete set
or gun barrels. Another method
e to cast the barrels OF steel
under immense pressure. A cheaper
twist grain barrel is made OF iron only.
The old-fashioned stubb and twist En-
giish barrel was made OF old horseshoe
nails. A still cheaper twist barrel is
made by inserting one end of square
rod OF steel in an immovable block and
che other end in the end of shaft,
which. when turned by steam power,
will twist the square rod into spiral
one. This is then bored out
Each of these processes, except the
one producing the plain barrel with
longitudinal fiber and the last one mem
toned, require deal of hand labor.
The last-rrentioned process makes a
poor fiber.
But the new process not only makes
q 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 arc
30 placed that 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 roll travels faster than the
surface at the small end. When. there
fore, a 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
Svryaa1in.y sr,.rAd ~ we'll ne 4.rsSt.ad
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 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 sSme time, but iron masters
of experience doubted its practical de-
velopment, so that it was not adopted
In practice by any one until within q
few months. The result of the new
process is sure to be the lowering o.
the cost. and probably thAI price, o
first-class guns, as well as those o
~ other grades 7. San.
S~