BREECH-LOADING ARMS AND NEEDLE.GUNS. To be loaded at the breech, and to be fired by the penetration of a needle into, or the impinging of a piston on, a detonat ing cap within the are distinct attributes in a weapon; and although it is only within the last forty years that the system has been carried out with success, breech loading arms have been tried, accepted, and abandoned without number during the last Jame centuries. Indeed, a sort of instinct dictates that loading at the breech is the pref erable course; and all the earliest muskets were so made, the system being doubtless abandoned from the difficulty of accurately closing the breech, in those days of rough workmanship. The extraordinary efficacy of breech-loading arms for military purpose& was brought prominently forward during the wars of the last few years, and notably in the Prussian campaigns of 1864 against Denmark, and of 1866 against Austria. The successes of the Prussian arms were attributed in no small degree to the rapidity with which their troops could fire as compared with the enemy. They had, in greater or less numbers, borne these same rifles since 1835, but these were the first opportunities of using them in warfare. To all the other powers, whose men still carried muzzle-loading rifles, and who had debated, without practical result, for years past the question of armament with breech-loaders, soldiers thus armed appeared irresistible. From July, 1866, to the present moment, the hammer and the anvil have been busy night and day throughout the civilized world in making the weapons of death yet more deadly. Scarcely two countries seem to have adopted the same plan: each nation has elaborated a system from among its own inventors. Those possessing no great reserve of rifles have prepared new arms; but the majority of governments have been content, in the first instance, to con vert their existing stock into breech-loaders of as good a construction as circumstances would permit. existing Britain, after offering a handsome prize for the best design, selected one said (subject to some eontroversy)'to be the invention of the late Mr. Snider. As this weapon has been produced already to the number of a million, and as it has con firmed the favorable auguries entertained of it by accuracy of fire, and by loading thrice to the muzzle-loader's once, much of the following article will be devoted to a considera tion of it. At the same time, it is to lie borne in following that the British government only regarded the Snider arm as a makeshift for the conversion of the enormous stock of Enfield rifles then in hand, reserving to itself the ultimate selection of a pattern on which to manufacture new weapons. It is not to be understood from what is said above that Britain adopted a breech-loading arm in a sort of panic after the battle of Sadowa. It was after the Danish campaign, on the 11th July, 1864, that it was decided as an abstract question to arm the British infantry with breech-loaders; a portion of the cavalry having for a number of years previously been armed with Sharp and Westley Richards carbines, loading at the breech. The selection of an arm took longer; but by the beginning of 1865 it had been decided to convert our great stock of rifles on the " Snider" system. In 1869 it was determined that new arms should be on the Martini-Henry system—i.e., with the Henry barrel, and the Martini-breech action. A description of this rifle will be given farther on.
Beeech-loading.—The advantage of breech-loading is obvious: to be able to insert the charge at the breech end instead of the muzzle, is to save time, and to avoid exposure to hostile fire during the operation of loading and ramming home, which involves consid erable outstretching of the limbs. The great condition of success is, that the bullet shall be propelled with equal force and accuracy, and with equal safety to the rifleman, as from the muzzle-loader.
When a charge is ignited, the constituents of the gunpowder, assuming a gaseous con dition under the heat engendered, expand into a volume of light gas many times greater in hulk than the powder before occupied. On the amount of this expansion, and its sudden action on the projectile, the force of the shot depends. Any joint in the breech piece through which a portion of this gas can escape, without having imparted its thrust to the ball, 'tends, therefore, to lessen the range and penetration; while the shock.of the
explosion falling more severely on this than on any other part of the barrel, tends yet more to dislocate the breech-piece, and diminish the closeness of the joint's fit. In weap ons which do not call for a long range, as revolver pistols, a perceptible interval is left betwccn the chamber and barrel, through which much gas escapes; but in rifles, which have range and penetration as principal objects, there is prima facie ground for preferring a muzzle-loader. The gas, however, is far from pure as generated in the barrel, for much water is produced and held in suspension, while there is also a solid residuum consisting of unburned materials of the powder. In the muzzle-loader, these clog (or, technically, foul) the barrel, filling the grooves, and rendering the ramming home of succeeding charges more and mare difficult. The effect is, that a solid mass of unburned matter is gradually forced by ramming into the head of the barrel, destroying the accu racy and usefulness of theweapon. In the breech-loader, this solid deposit must be pro vided against both ways. The backward throw on firing (for, of course, the charge explodes with equal power in every direction) tends to force it into the mechanism of the joints, preventing their proper fit. and continually augmenting the escape of gas; and m the other hand, preventing deposit in front is most detrimental to accuracy of fire. This protection of the breech-apparatus, the prevention of fouling, and the retaining and if possible the force and fire, were the problems which inventors have had to solve. =nib. Calif - linintymnft • A moderate escape of gas in front of the first position of the ball, is not found to be any material disadvantage. If, then, the barrel could have an opening where the cartridge could be inserted, and then pushed backwards, an escape of gas through the joints by which the opening might be subsequently closed would be comparatively immaterial; but this formation would be impracticable, because the explosion of each cartridge would drive the fouling more and more backwards, till ultimately the cham ber at the breech would be unable to contain the cartridge. It is clear, therefore, that the charge must be inserted either at the barrel's head, or, if the barrel be opened, in a space close to the barrel's head. In either of these eases, the breech must be solidly closed to resist the explosion. A third case, as in the Snider, is where the cartridge is inserted and then pushed forward, the aperture being closed by a solid breech-piece which coin pletely tills that portion of the barrel, and forms, with the barrel's head, a massive foot to resist the backward pressure of the fired powder. No breech action can be made to fit so accurately as to prevent a backward escape of gas unless a properly-constructed cartridge-case is used A perpendicular moving joint is found, in practice, to be the best adapted for preventing a serious escape of gas. In the Prussian needle-gun, the end of the barrel is the frustum of a cone, which fits into a corresponding cavity in the fore-end of the breech-piece, but in practice this joint is not sufficiently tight to pre vent an escape of gas from the self-consuming cartridge used with this gun, which becomes inconveniently great after long use of the weapon, and it is only available when the breech-piece is pushed up from the rear. In the Snider and several other breech loading weapons, the cartridge is made itself to close hermetically the aperture between the barrel and the fore-end of the breech-piece. This is effected by the expansion of the .^.artridge-case, which, being composed of metal, or a combination of metal and paper, is driven out by the force of the explosion till it completely fills the chamber and prevents any escape backwards between the sides of the case and the chamber. The cartridge has a portion of its case at the base flattened out into a rim which fits into a correspond ing recess in the end of the barrel; and to prevent expansion backwards, which would fracture the cartridge-case, and injure the breech or the firer. the breech-piece is made to fit as closely as possible against this base. This rim is on the Snider cartridge.