In 1854 Sir W. Armstrong brought forward a breech-loading rifle gun, his plan was accepted, and a gun of small calibre having been made according to it, was tried at Shoeburyness. With some modifi cations this description of gun has been adopted in the British service, and found very efficient iu the late China war. In fact it is the most perfect gun yet adopted in any artillery. The following description of the original gun tried at Shoeburyness, and at Sir W. Armstrong's private factory at Newcastle, is taken from the minutes of Proceedings of the 'Royal Artillery Institution,' given in the Elementary Lectures on-Artillery for the Royal Military Academy,' by Major Owen, 11.A., and Captain Dames, 11.A. ; from which also, and a paper on the ' Con struction of Artillery,' printed by the Institution of Civil Engineers, the description and drawings of gun, shell, &e , are taken :— " A core or internal titling was formed of caststeel, to which the requisite strength was given by encircling it with twisted cylinders of wrought-iron made in a similar manner to gun barrels, and tightly contracted upon the steel core by the usual process of cooling after previous expansion by heat; the parts are then in a state of initial tension, which is necessary to bring their entire strength into operation. The arrangement for loading at the breech consists of a powerful screw having a hole through the centre in the prolonged axis of the bore, through which hole the bullet and charge are delivered into the gun. A " breech-piece" with a mitred face fitting a similar face at the end of the bore, is dropped into a recess, and by the action of the screw pressed tightly into its seat, so as to effectually close the bore. The fitting surfaces which close the bore were at first made of unhardened steel : this failed; hardened steel was next used, but this yielded to the action of the powder more rapidly than before; copper was theu tried, and uo further difficulty was experienced. The breech-piece contains the vent.. The bore of the gun was J. inches in diameter, and contained eight spiral grooves, having an inclination of one turn in 12 feet ; these grooves terminated at a distance of ]6 inches from the breech, and the bore then gradually expands in a length of 3 inches from 11 inch to 11 inch in diameter." The gun weighed about 5 cwt.
The projectile, which is cylindro-conoidal in form, was Gi inches long, and weighed 5 lbs. ; it was of cast-iron coated with lead, and was hollow, so as to be used either as shot or shell. It was slightly larger in diameter than the bore of the gun, and being inserted at the breech took Its rifling by being forced through the grooved bore.
The charge was one-eighth weight of shot. The following results of experiment. are given in the 'Lectures' before mentioned :—Fourteen projectiles were fired at a butt of wood 5 feet wide and 7 high from a distance of 1500 yards. Six shots were fired as trial shots to obtain the correct elevation. The remaining eight hit the butt without grazing, the elevation of the gun being 4' 26', and the mean deflection from the centre hue on the butt was only inches. The experiments with shells fired at two targets, placed 30 feet apart, covering one another, were equally remarkable—nesrlyall the shells passing through the first target and bursting before reaching the second.
This being a small gun was of course may of manufacture, but Sir W. Armstrong has been equally successful in making 12, 25, 32, and 40 pounders; and experiment.' are now being made with much heavier
gurus 70, 80, and 100 pounders The 12 pounder is the gun adopted for the field batteries and horse artillery. Those used in China have weighed 6 cwt.., with a charge of 1 lb. R oz. It is probable that in future the 8 cwt. gun, with a charge of 1 Ih. 8 oz., will ho adopted. The guns are now made wholly of wrought Iron, and in order to avoid the difficulty of forging very large manses they are made in piece's tubes from 2 feet to 5 feet long, which are then welded together. The tubes ore formed by winding long lam of heated iron round a roller, the coil is then brought to a welding beat and hammered together ; the edges of the coils or tubes tiering been bevelled off, the tube,' are welded together. The manu facture is very complicated. The finished pm is shown in fig. 1. The grooves are very narrow and shallow. The driving sides, that is to say, the sides the projectile bears on in passing out of the gun, are cut square, or at least radial, the other edges are rounded oft'.
The width of the lands and grooves being the same, they vary in number according to the calibre of the piece,—the 12 pounder has 34, the larger guns have more,—they make about half a turn in the length of the piece, and the charge seems to be about Ith the weight of the projectile. The construction of the projectile, which is shown in Sig. 2, has been thus described by Sir W. Armstrong. " The projectile consists of a very thin cast-iron shell, the interior of which is composed of forty-two segment-shaped pieces of cast iron built up in layers around a cylindrical cavity in the centre, which contains the berating charge and the concussion arrangement. The exterior of the shell is thinly coated with lead, which is applied by placing the shell in a mould and pouring melted lead round it. The lead is allowed to percolate among the segments, so as to fill up the inter stices, the central cavity being kept open by the insertion of a steel core. In this state the projectile is so compact that it might be fired through 6 feet of hard timber without injury, while its resistance to a bursting force is so small that loss than one ounce of powder is sufficient to break it in pieces." It is a great advantage for service to have a projectile of this description, which can be used as shot, alien, /shrapnel!, or case. The simplicity of ammunition is perfect when one form serves all the purposes that can be required, for it is only necessary in using it as shot not to put in a fuze. The shell can, as will be seen, be made, according to the fuze, either a time shell or a coticastion shell. By adjusting the fuze so as to burst the shell just abort of the object, we have a ehraptiell of the most perfect de scription, for a small bursting charge will liberate the numerous seg ments of which the shell is formed; while, by adjusting the fuze so CIA to burst the shell at the muzzle, we may use it as case. Sir W. Armstrong stated in a speech he made at Newcastle, that the shell burst into 49 regular pieces and about 100 irregular pieces. And also that for breaching purposes, firing at buildings and ships, a different construction of shell was adopted, the object being to introduce the largest possible charge of powder. The shell of the Armstrong 32 puunder contains about twice as much powder as that of the ordinary 32-pounder.