Gun- 
making. 
Process of 
Doring. 
560 
has undergone the same operation, and is rendered as 
perfectly Snkinedns as if TO had been bored out of a 
solid piece. Twisted barrels are now generally used 
for the finest fowling-pieces, the method of fabricating 
_of which is as follows. . Four bars of stub iron, two feet 
‘in length, half an inch in breadth, and the first two bars 
half an inch thick or more, according to the size of the 
barrel, are previously prepared, An old barrel being 
welded to the extremity of one of those bars fora handle, 
‘it is heated and turned round like a cork-screw, by 
means of the hammer and anvil; after this, the turns 
-of the spiral are united by heating the tube two or 
three inchés at a time to a bright white heat, and 
striking the end of it several times against the anvil ina 
horizontal direction, with considerable force: This is 
called jumping the barrel, and the heats given for that 
purpose jumping heats: A mandril is immediately in- 
‘troduced into the cavity, and a quick light hammering is 
kept up on the welding part, until the ridges raised at 
the seams by the jumping are flattened, and the piece 
appears sound. As soon as one bar is rounded and 
jumped in this manner, another is. welded to it, and 
“treated in the same way, until the four pieces are united 
and form one tube: The old barrel is then cut off as 
being no longer requisite, and the operation of heating 
and hammering is frequently repeated in its whole 
length, until its external figure is correctly acquired, 
and the metal has arrived at the utmost closeness of 
fibre in all its parts. . It is a circumstance of consider- 
able importance with respect to a gun barrel, that it 
should be forged as nearly as possible to its weight 
when finished, so that very little may be taken away in 
the boring and filing ; for as the outer surface, by ha- 
ving undergone the action of the hammer more imme- 
diately than any other part, is rendered more com- 
pact and pure; the less that is removed the better will 
the barrel be: - 
The next process is the boring, the apparatus for 
which is either driven by a water wheel, steam en- 
gine, or the hand, according to the extent of the manu- 
facturer’s. demand. This operation consists in giving’ to 
the barrel its proper calibre. The boring bit is a rod of 
iron, somewhat longer than the barrel, one end being 
fitted into the socket of the crank, and the other fiir- 
nished with a cylindrical plug of tempered steel, about 
an inch and a half long, and having its surface cut with 
spiral grooves, flat at bottom, and a quarter of an inch 
in breadth. This form gives the bit a very strong hold 
of the metal, and the threads sharp at the edges; scoop 
out and remove every roughness and inequality from 
the inside of the barrel, and render the cavity smooth 
and equal throughout. Several bits, each a little larger 
than the prechtinig one, are afterwards successively 
passed through the barrel in the same way, until it has 
acquired the intended calibre. After this the fine 
boring bit is ‘introduced, being a similar rod to the 
former, with a square bar of tempered steel, 10 or 12 
inches long atits extremity, and finely sharpened on one 
of its sides ; on the opposite side is placed a semicircu- 
lar slip of wood, of a size sufficient to fill up with the 
bit the entire diameter of the barrel, two of its. edges 
only acting on the tube, which ‘passing through its 
whole length, and kept well oiled, is frequently re- 
peated, and the bore enlarged by small slips of paper 
placed between the wood and the bit, until the inside 
presents a perfectly equal and polished surface. The 
trueness of the bore is then proved, either by a steel or 
leaden plug passed through its whole length. The 
next step towards completing the barrel is the operas 
>in his hands, presses the barrel to the’ stone, w 
GUNMAKING. 
tion on its exterior surface, which in common barrels is Gu 
done by grinding on a large stone ; two steel pins 
+ 
inserted into the mouth and breach of the. cabana 
smaller than its diameter. The workman 
Té-= 
volving on the » grinds ‘off the inequalities left 
the hammer ; after which it is passed Torarichas perebe 
who files and smooths it from one end to the other, © 
The best barrel makers do ‘not grind; but tarn their 
barrels on a lathe, which is well calculated to insure 
that perfect equality of thickness on which the strength 
and safety of the piece so greatly depend. The filin; 
is afterwards performed in the 
and smoothing is 
manner. 
liable, and which render them «dangerous to use, 
and apt to burst, are the chink, eee The 
first is a small rent in the direction the length 
of the barrel, the second across it, and the third is a 
scale or plate adhering to the barrel, by a narrow base, 
from which it spreads out like the head of a nail from 
The imperfections to which gun barrels are 
its shank, and when separated leaves a pit or hollow in | 
the metal.. Chinks or flaws are of much worse conse= 
quence than the crack in fire-arms, the expansive force 
of the der being exerted more upon the circum. 
ference than the length of the barrel; the flaw is much 
more frequent than the chink, the latter ever 
occurring but in plain barrels, formed out ofa single 
plate of iron, The proof of gun-barrels, tsidhiannaliat 
and fowling pieces, as established by Government and 
the Gunmakers Company of London, is a ball that fits 
the diameter of the piece, and a charge of powder of 
equal weight, which being fired, either bursts the bar- 
rel, or demonstrates its soundness and ‘safety. Some 
gunmakers are in the habit of sr 4 a= test, b 
water proof, in order to ascertain if the pores of the 
‘by a 
7 
x 
metal continue perfectly secure. Pistol barrels are — 
forged in one piece, two at a time, joined by their 
muzzles, and are bored before they ate cut asunder, by 
which means there is not only a saving of time and la- 
bour, but a greater certainty of*the bores being the 
same. 
have the merit of this contrivance. 
of Kuchanrieter senior of Ratisbon are in the test 
esteem; and so fond are the Germans of excelling in 
the use of the rifle, that it has become one Of their 
principal amusements, in which all ranks of society fre= 
quently indulge. Every town and vil has their 
practising ground, or butts, where small prizes are com= 
peted for, with an accuracy of aim that is in 
prizing. The Americans have also, from their habits of 
hunting, acquired great correctness in the use’ of rifle 
guns ; and within these few years our government has 
introduced them into the army; the ese ter regi 
ment being peculiarly clothed, and armed with that 
weapon. ‘The manufacture of rifles; in their first for 
mation, is exactly similar to that of other barrels, ex 
cept that their external) form is generally octagona 
The process of rifling is as follows ; the barrel 
previously bored, and finished to a true cylindric: 
form, is placed on the rifling machine, an instrument 
formed on a square plank of wood seven feet long, to 
which is fitted a tube about an inch in diameter, with 
spiral grooves deeply cut internally through its whole 
length, and to which is'attached'a circular plate, about 
five inches diameter, accurately divided in concentric 
circles, into from five to ten equal , and supported 
_by two rings affixed to the plank, in which it revolves ; 
an arm connected with the dividing plate, and pierced 
nal. 
Rifle barrels are of modern invention: The Cettntes ning 4 
The rifle barrels barre! 
rifling, 
