CONSTRUCTION OF SHOTGUNS
In treating briefly of shotgun construction I shall make no pretense
of posing as an expert in their manufacture. There are many things
connected with the building of guns about which our manufacturers talk
with reluctance, such as the prices paid for raw material, wages given
to workmen, actual cost of turning out a gun of a certain grade, amount
of hand work placed on any particular arm, and other things. All this
would be of little value to the amateur if known and might possibly
embarrass the factory owners. My only endeavor here will be to give the
novice an idea of how guns are constructed sufficiently clear to permit
him to judge with fair accuracy his own arm or any that falls under his
observation.
Barrels being a prime factor in gun building, we may as well begin with
them.
BARRELS
(Damascus, Twist, Laminated, Compressed Steel.)
Up to a decade or so ago shotgun barrels were made of a combination
of iron and steel strips, welded together and then twisted around
a mandrel of such size as roughly to give the diameter of the bore.
After being twisted into a spiral tube this was hammered or welded into
a homogeneous mass. These tubes were known as twist, laminated, or
damascus, depending upon the manner of using the steel and iron. The
damascus barrels were further subdivided into two-stripe, three-stripe,
and four-stripe damascus, the numerals having reference to the number
of strips of iron and steel that were welded together before being
twisted.
It is an old story that in the original, handforged barrels horseshoe
nails were used, and it was popularly believed that they made the
strongest and toughest barrels. Perhaps such material really entered
into the construction of gun barrels, but it is not worth while to
attempt either to prove or disprove the tale now.
Damascus barrels were in high favor twenty years ago. They were
very tough and elastic, capable of expanding under pressure without
disrupting. The only fault to be found with them is that they are soft,
denting easily, when struck against another barrel or any hard object.
Frequently gunners injured one another’s damascus tubes by jostling as
they walked side by side.
As compared with modern fluid steel barrels those of damascus were also
more liable to be injured by the gases of nitro powder, and generally
they were hard to keep free from pits and rust. It is doubtful, too,
if they would take as high a degree of polish as those of our present
plain steel. It is the belief of the writer that except for the regard
of the conservative for what was known to be good, no damascus or twist
barrels would now be in use.
COMPRESSED STEEL
The plain rolled or drawn steel barrels are known to be harder than
any heretofore used, thus being less liable to accidental injury. They
will sustain a higher internal or chamber pressure than damascus, and
are therefore better adapted to nitro powders with the occasional high
pressure that may be developed by handloaded or experimental charges.
Such tubes will take a higher polish, and can be kept free of pits with
half the labor occasioned by the old combinations of steel and iron.
The process of manufacture is simpler, and good barrels can be turned
out at a much reduced cost. The choke of a steel barrel can never be
shot out and will retain its pattern for all time.
Our manufacturers have various technical names to describe their
different grades of steel barrels. The Krupp and Whitworth tubes,
made in Germany and England respectively, have perhaps the greatest
repute. Other grades of steel such as armor, nitro, high-pressure,
titanic, homo-tensile, vulcan, mean nothing to the outsider more than
that they are known to be placed upon certain grades of weapons by
reliable manufacturers. Probably there is quite a difference in the
pressure that the cheaper and the higher grades of compressed steel
will sustain, but in its finished state the ordinary observer cannot
detect any difference in the appearance of the grades as he could with
the damascus and thus must rely solely upon the manufacturer’s word and
reputation for the quality of his gun barrels.
While I should have absolute confidence in the safety of any barrel
placed upon an arm by a reputable manufacturer, yet it is to be
regretted that builders regard as “trade secrets” the different
pressures that various grades of steel will bear. It might be well
for a man to know just how close he was coming to the danger line in
shooting heavy loads.
Some gunmakers advertise their barrels as being able to withstand a
pressure of one hundred thousand pounds to the square inch, but it is
difficult to understand just what this means. If the barrel would bear
an inside pressure of a hundred thousand pounds, it would, indeed, be
a corker. The ordinary shotgun charge only develops a pressure of from
four to six thousand pounds, and the barrel is “proved” in the rough
with a pressure of from four to five tons.
In this country we have no government proof house such as all European
countries possess, and hence must rely upon the tubes being privately
proved by the different manufacturers.
Strangely enough, while we turn out more shotguns than all the
remaining world put together, we are not and never have been a
barrel-making nation. Just why this should be true I am unable to
state, but the majority of our tubes are imported from Europe in a
rough form and are then put together, filed, shaped, and bored in this
country. It appears only a question of a short time now when America
will forge her own barrels. The Stevens people are now making all the
tubes used in their factory, and the Winchester and Remington factories
those adapted to their repeating shotguns.
The fluid or plain steel barrels are manufactured from a solid bar.
This is first drilled through and then rolled or drawn into length or
shape; after which it is rough bored into a size some thousandths of
an inch smaller inside diameter than it will be when finished. It is
then subjected to its first proof test which is expected to develop a
pressure some three times as high as the tube will be called upon to
bear with standard loads. This first test is cut upon the barrel in the
shape of a “proof mark,” and it is then in shape to be exported. Should
the barrel be finished in Europe, it will be given a final government
proof in its finished condition, this proof developing double the
bursting strain of normal charges.
In this country, having no government proofhouse, we must rely, first,
upon the foreign proof-marks, and, second, upon the reliability of our
builders. The foreign proof mark is practically worthless, for the
reason that the barrel is afterwards filed down and shaped, and if this
is unskilfully done a barrel that had ample strength in the rough might
be so weakened as to become absolutely dangerous. Within the past few
years I have seen a barrel burst that was as thin at the point where it
disrupted as the paper upon which this is written. It follows that our
only reliance is upon the integrity of our manufacturers, and ordinary
precaution would require that we purchase an arm only from men who have
a reputation to jeopardize.
It is greatly to our manufacturers’ credit that their output has
always been of such quality that there has been little demand for a
government proofhouse. Doubtless, though, should we ever become a large
exporting nation, which seems probable, such an institution will have
to come.
[Illustration: Stevens barrels ready to braze]
[Illustration: Stevens barrels finished]
[Illustration: Stevens compressed steel barrels. Barrels and lug forged
in one piece]
FINISHING BARRELS
The rough tube as it comes from the maker has little resemblance to
a finished shotgun barrel. A large amount of skilled labor and the
services of a number of special artisans are required before the
tube is ready to burn nitro powder and drive shot. The barrels must
first be filed down and dressed into the shape that gives them that
elegant taper from breech to muzzle, and while cutting away, reducing
weight and shaping them the greatest care is taken to do the work
scientifically, leaving a thickness of metal where the greatest strain
is to come, the whole work being accomplished by a man whose sole duty
or trade is to do that very thing.
Then another expert puts the barrels together, and upon his skill
depends the accurate shooting of the barrels, that is their shooting
to center. I can well remember the dismay of a young friend of mine
who discovered after a year’s use of the weapon that one barrel shot
six inches lower than the other at twenty-five yards. Of course he no
longer had any confidence in that gun, nor had he any difficulty in
accounting for every miss made during all of the year.
GUN BORING AND POLISHING
Some of our shotgun borers have international reputations, and
certainly they have made greater advances in their profession than have
the artisans engaged in any other branch of gun building. It is said
that the most skilled of these men can regularly cut a barrel to a
thousandth of an inch at any point from breech to muzzle, guaranteeing
a pattern within a very few pellets of that demanded. Not every shotgun
barrel is cut alike, indeed every gunborer has a system of his own that
will differ at least in minor particulars from those of all others, but
results are practically similar. It is true that nearly all the above
work is accomplished by machinery, but it is machinery that requires
very intelligent supervision.
When the barrels are bored the polishing process begins, and upon the
manner in which this is accomplished depends the interior beauty of
the tube and to some extent its future usefulness and life. A highly
polished bore is perhaps the best of all guarantees against pitting
and rusting. Moreover, this polish is strictly necessary in order to
guard against the piece leading at every discharge. I have seen barrels
that would begin to lead with the first shot and steadily increase the
deposits until from a seventy per cent. tube the pattern was reduced
to one of fifty per cent. Of course faulty ammunition might have
something to do with this, but it remains that some barrels lead much
more than others with the same ammunition.
Leading a gun seems to be a necessary evil, not to be entirely obviated
by the most conscientious work. Possibly one system of boring may show
better results in this respect than another, though I have never yet
seen a barrel that would not show traces of lead if shot rapidly enough
to heat. It is a very disagreeable fault, rendering the piece hard to
clean and causing pits where the tube is neglected, as well as reducing
the pattern as mentioned. In fact, I have yet to see a gun that would
maintain its seventy per cent. pattern throughout a day’s shooting.
Perhaps the cone has as much to do with the leading of a barrel as
any other feature of the bore. The cone is the place where the barrel
narrows from the shell chamber to its true bore. Should this be of
faulty shape it may cause the charge to upset as it enters the barrel,
leaving a deposit of lead at the breech. When the shot have jammed
and leaded in entering the barrel they are in good condition to make
further deposits; as a consequence the piece that leads in front of the
shell chamber will nearly always do so in the choke as well.
BARREL FITTING
Our barrels are now fitted to their action, and here the work can by no
means be slighted without betraying its slovenly character even to the
novice. Barrels perfectly fitted to the frame are sufficient evidence
that no part of the work of the entire arm has been neglected. Where
steel and iron come together the fitting should be as fine as the edge
of the sharpest tool, so close that eye can scarcely observe the joint.
An expert judges the arm from the way it is fitted as accurately as a
naturalist can pronounce upon the character of an animal from its teeth
and jaw. If the tyro can observe any evidence of imperfect fitting then
it is a cheap gun, no matter by whom made or at what price.
COST OF BARRELS--ROUGH AND FINISHED
Barrels cost in the rough as imported from two to twenty-five dollars
a pair. When finished and adjusted to the frame they range in price
from ten to two hundred and fifty dollars. Usually our builders charge
one-half the price of the arm for an extra pair of barrels of a grade
similar to that of the gun. Many of the manufacturers refuse to cross
their grades by placing cheap barrels upon a high grade arm or vice
versa.