Pivot gun

“ It gives ease and speed in the manipulation of the piece in traverse, but has the disadvantage of rendering the carriage less stable in firing due to the fact that the direction of recoil of the gun is in the direction of the line joining the trail spade and the central pivot, only when the gun is absolutely in the center of its traverse. In all other positions, which will be the usual case, there is a component at right angles to the line of trail spade-central pivot which tends to throw the gun off from its proper direction making it necessary to relay each time the gun is fired. ”

“ Movement of the gun in traverse is accomplished in two general ways.
(a) Pivot on the gun carriage axle.
1. The gun and cradle move around a vertical pintle or pivot placed in a saddle or rocker which itself pivots on horizontal trunnions or bearings usually attached to the axle. The rear end of the rocker forms a seat or bearing on which the cradle and gun move in traverse. The upper end of the elevating screw is also attached to the rear end of the rocker. This allows the rocker and cradle to be moved together in elevation and the cradle to move on the rocker in traverse. ”

“ The recoil and pulling the trigger throw back the right shoulder, which tend to increase the “derivation” to the right. If the twist were, then, from right to left, the drift, error from pulling, and from recoil, would tend to neutralize each other; the twist of the grooves should therefore be from right to left, instead of the present universal practice of from left to right.
On length of barrel.
The barrel of a gun may be looked upon as a machine in which force is generated for the propulsion of the bullet. ”

“ Each barrel has its own breech-plug, striker, spring, and extractor, and each fires independently of the rest, so that all are not out of action together. The gun has a swivelled mount easily elevated and trained, and the steel frames take up the force of the discharge. In rapid firing one gunner [Pg 99] can work the firing-handle while another lays and alters the direction. The firing is operated by a lever working backwards and forwards by hand, and the gun can be discharged at the rate of 600 rounds per minute. ”

“ There are several other types of machine guns, but the most ingenious, and perhaps the most effective, is the Maxim automatic gun. This has a single barrel, about two thirds of which, from the muzzle towards the breech, is surrounded by a water-jacket into which water is automatically injected at each discharge, thus rendering overheating impossible. The mechanism for operating the gun is at the breech, covering the remaining third of the barrel. All that is necessary is to draw back the trigger to fire the first shot ”

“ When the country is flat or the features devoid of natural cover, it will be necessary to provide pits for the machine guns practically in the firing line. If this is carried out with skill, the guns may be perfectly concealed, and protected even from artillery fire. These pits should be made along the whole front and as widely scattered as possible, and when a gun is discovered by the artillery it should immediately be lowered into the pit, out of sight, where it will be perfectly safe, until the artillery directs its fire elsewhere. ”

“ If within three, four or five inches from the muzzle, the portion so destroyed can be sawed off, the barrels squared up and it will not always seriously affect the shooting of the gun.
In loading a gun be careful that there be no air space left between the charge and the ball or shot cartridge. In double guns, frequent firing the right [138] barrel, which is the one fired the most, the recoil will often cause the ball or shot charge in the left barrel to be thrown forward from the powder, and when it is fired may either strain or burst the barrel. ”

“ It first must be understood that all modern guns on ships-of-war are breech-loading and rifled, and that the smooth bore exists only as a relic, or to be brought out in an emergency for coast defense, when modern guns are not available. From the thirteen-inch down to the four-inch, the guns are designated by their caliber, the diameter of their bore, and the shot they throw, while from that to the one-pounder they take their name from the weight of the shot. Everything below the one-pounder is in the machine-gun class. ”

“ The old, smooth-bore field-guns of the enemy would be completely disabled before they could be brought within cannon-shot of the ten thousand. As soon as the enemy came within rifle range, the ten thousand would open on them with their thousand automatic machine-guns and magazine-rifles. As an automatic machine-gun fires at the rate of 600 shots a minute, a thousand would fire at the rate of 600,000 shots a minute. The magazine shoulder-rifles would fire aimed shots at the rate of twenty-five a minute, and the quick-firing field-guns would each fire shrapnel at the rate of forty a minute. ”

“ The English gun-smiths avoided the dilemma by giving the requisite pitch and making the grooves very deep, and even by having wings or lugs cast on the ball to keep it in the grooves—expedients which increase the friction in the barrel and the resistance of the air enormously.
The American gun-makers solved the problem by adopting the “gaining twist,” in which the grooves start from the breech nearly parallel to the axis of the barrel, and gradually increase the spiral, until, at the muzzle, it has the pitch of one revolution in three to four; the pitch being greater as the bore is less. ”

“ Old guns which have been laid by will not uncommonly be found spiked, by having a common nail driven into the vent. If efficient tools are at hand this may be drilled out, if not, put a charge of powder in the gun, bore a gimlet hole in one of your wooden wads, through which pass a loosely-twisted string well impregnated with dissolved gunpowder, and afterwards dried. Cut the end of your prepared string just at the muzzle of the gun, light it, and get out of the way, when the explosion, which soon takes place, will not unfrequently expel the spike. ”

“ The spin of the bullet keeps its nose pointing forward. If it were not for the rifling, the bullet would tumble over and over, every which way, and it could not go very far through the air, to say nothing of penetrating steel armor. To gain the spinning-motion the bullet must fit into the barrel snugly enough to squeeze into the spiral grooves. Now there is another American machine-gun known as the Hotchkiss, which was used to a considerable extent by the French Army. It is a gas-operated gun, something like the Colt, and it is air-cooled. ”

“ This accuracy may be obtained to 30 or 40 yards provided that the bullet is sufficiently large to enter the chamber, but a size too large for the muzzle. It will accordingly squeeze its way through without the slightest windage, and will shoot with great precision, with a charge of 4 1/2 drams of powder and a ball of pure soft lead. A No. 12 is exceedingly powerful, and if 7 lbs. in weight, it can be fired with one hand like a pistol. This is an immense advantage, as the shooter can hold tight by the howdah rail with his left hand, while he uses his gun with the right. ”

“ In sporting guns snow may accidentally get into the muzzle or a lump of dirt may “somehow” get in so as to fill the bore, and when the gun is fired, it will probably, yes, most certainly be blown off or blown open where the obstruction exists; the muzzle of a gun being thrust into water for a couple of inches or more will have like effect. The gas formed by burning the powder finds no outlet of escape, and the whole expansive force concentrates itself on the weakest portion of the barrel, and as a result it is forced apart. ”

“ Many patents have already been taken out for rifles on this principle, and several patterns have actually been constructed, in which a merely momentary contact of the breech-piece with the end of the barrel is sufficient; the recoil of the barrel with the reaction of a spring performs all the requisite movements with such rapidity that an amazing speed of firing has been obtained. It is said that such an automatic gun can send forth bullets at a perfectly amazing rate. ”

“ In loading a rifle the powder is first measured in a “charger,” and then poured down the barrel; next comes the patch, which is usually a piece of new and strong cotton cloth, most commonly the kind known as white drilling. This, having been tallowed upon one side, the tallowed side is spread over the muzzle of the gun, and the bullet is pressed upon it into the muzzle, the side from which the “neck,” formed in moulding, has been cut, must be directly downward. Generally with the handle of a knife the bullet is pressed into the bore as far as it can be sent by such means ”

“ The modern long-range guns and improved howitzers [Pg 85] have, however, virtually superseded mortars. Machine-guns of various forms are comparatively small and light, transportable by hand, and filling a place between cannon and small-arms, the latter term embracing the soldier’s personal armament of rifle and pistol or revolver, which are carried in the hand.
A group of guns of the like design are generally given the name of their first inventor, or the place of manufacture: such as the Armstrong gun, the Vickers-Maxim, the Martini-Henry rifle, or the Enfield. ”

“ The gun’s narrow frontage in action renders it easy to conceal, and when discovered it presents a very small and difficult target to the enemy’s riflemen; on the other hand, when once discovered if it cannot be moved unseen to another position it is liable to suffer a prolonged and concentrated fire from the widely scattered riflemen of the enemy, to which it cannot effectively reply, and which must in time cause loss. Again, its range being limited, it is powerless against artillery except under special circumstances at effective rifle range. ”

“ Mortars with iron beds immoveably fixed in the earth throw their shot to greater distances than guns which are affixed to carriages can do, and which, therefore, can recoil. This has been [320] incontestibly proved, both in large and small artillery. Having suspended a gun barrel, charged with a determinate quantity of shot, from the ceiling by two cords, so as to allow of its recoil, fire it point blank at a target, and mark the result accurately. ”

“ A small part of the gas generated by the explosion of the individual cartridge operates the mechanism, discharging the bullet, throwing out the empty shell and making ready for the next shot.
A machine gun is designed to enable one man to fire the equivalent of a volley, or series of volleys, discharged by an entire platoon (one-third of a company) of infantrymen. As at present developed, it represents a step toward the evolution of a shoulder-rifle that will throw a continuous stream of bullets. ”

“ The gun is a remarkable object among the rest of our artillery. Its barrel, immensely long but very slender, has a well-bred, aristocratic look compared with the thick noses of our field-guns. It drives its forty-five pound shell about seven miles, and shoots, I am told, with perfect accuracy. It is an enlarged edition of the beautiful little twelve-pounders which we have hitherto been using, and which exceed the range of our fifteen-pounder field-guns by about a half. Why should naval guns be so vastly superior to land ones? ”

“ The principles which should govern the construction of a gun to discharge projectiles so as to obtain the maximum of range and accuracy with a given propelling power, hold good alike both in machine guns and hand guns. The best properties of the hand gun are the best also for the wheel guns. By the discharge of powder force operates in three ways: to make the gun recoil; to expand the barrel laterally, with a tendency to rend it open ”

“ Within effective range, however, machine guns, if concealed, should inflict considerable loss on hostile artillery. Engagements with their lines of skirmishers should be avoided, for the risk of disclosing the position of the guns and the heavy expenditure of ammunition involved will rarely be justified by results. Since the gun is not well adapted for keeping up protracted fire, it may be often expedient to withdraw it from action, move it elsewhere, or hold it in reserve for a more favourable opportunity. ”

“ If a pin gun the pin should fit in the hole with nicety. If too tight, the barrels might not close, or the pin might be held back to such an extent that the cap would not be exploded. If too loose an unnecessary escape of gas at the discharge would be unavoidable, to the discomfort of the gunner and the weakening of the shot.
If a central fire the plungers should strike the centre of the cap unvaryingly. The hammer should come upon the plunger with a blow—not a mere push. ”

“ One of the old arrangements, often laughed at, I mean the bell muzzle in old guns, intimates that our ancestors possessed some smattering of science; as the relief in the muzzle of a gun has a tendency, by allowing a gradual expansion laterally, to keep the charge of shot better together: for it is quite apparent that any body severely compressed for a certain distance, expands in proportion when free of that restraint; and the consequence is a tendency to fly off at a tangent, as the friction of a [307] crooked barrel induces a ball to fly in a curve contrary to the bend of the barrel. ”