In this rifle barrel were two grooves, making one turn in its 3o in. of length, the twist. thus being four times steeper than that in the Baker rifle. The projectile it fired was a ball, round which was a belt. The latter, travelling in the grooves, imparted a spin to the bullet. One of the advantages claimed for this rifle was that a more rapid spin could be imparted to the bullet, as, owing to its belt working in the grooves, there was no fear of this leaden ball stripping or riding over the rifling. Much thought was devoted to the questions of the most effective twist, and the best number of grooves, coupled with the desirability of increasing rapidity of loading by devising a pro jectile which would pass easily down the bore and would yet, when fired, expand into the grooving.
In 1826, Delvigne, a French infantry officer, invented a chamber with abrupt shoulders on which the spherical bullet was rammed down until, expanding, it fitted the grooves. The line of development which the bullets took was twofold, namely, making them long with rounded or ogival noses, and also cupping their bases, with or without metal or wooden plugs positioned inside these cups. The gases on meeting these bases expanded the cupped bullet, or else forced the plug to expand the bases of the bullet, and so sealed the bore.
The "Minie" rifle, in which this bullet was first demonstrated, had no devices in the bore for expanding the bullet, reliance being placed on the action of the gas pressure on the base of the bullet to "set up" the base, and so seal the bore. This principle has been adopted practically ever since for small arms. The Minie rifle was a success and was adopted by France and Belgium, the United States, also by the British Government in 1850-51, and was entitled the Regulation Minie Musket. This rifle was employed in the Kaffir War of 1851 and also in the Crimea. Its weight with bayonet was Io lb. 84 oz., the barrel 39 in. long, having four grooves making one turn in 72 in., and the bore was .702 inches. It was sighted for from ioo to i,000 yards.
Ten years before the adoption of the Minie rifle, however, Prussia led the way by adopting the Dreyse needle gun. This was a breech-loading bolt action, provided with a long needle carried in a slender rod which was actuated by a surrounding spring. On pulling the trigger the rod flew forward, and the needle, passing through a guide in the front of the bolt, struck a disc of detonating material, so igniting the charge. This was the system initiated in England by Forsyth in 1805. This early pattern suffered certain defects; for example, after a few rounds, owing to the escape of gas and flame between the breech and bolt, the rifleman could not continue firing from the shoulder. Also, the needles rusted and broke; yet the gain in rapidity of loading was considered to outweigh greatly the above defects, and this rifle was the general arm of the Prussian and German troops in the wars of 1848, 1866 and 1870.
In 1855, the Enfield rifle, made in the Royal Small Arms Factory, was introduced into the British army, after it had been tested against others made by private firms, to which it was found to be superior ; and in the Crimea it super seded the rifled musket and the Minie. In turn the Enfield rifle
was tried at Hythe against one made under the auspices of Sir Joseph Whitworth in 1857, which proved to be much superior. This Whitworth rifle had a hexagonal bore of -45 in. calibre rifled to one turn in 20 inches. Induced by the commander-in chief, Lord Hardinge, Sir Joseph Whitworth had devoted himself to a long series of experiments to investigate the subject of rifling, which culminated in his demonstrating the advantages to be gained from spiral rifling, a small bore and an elongated projectile. Despite this, the Whitworth rifle, which embodied these features, was never generally introduced into the service, although advantage was taken of the lessons he taught. Between the years 1857 and 1861 four breech-loading carbines were introduced into the cavalry experimentally. These were Sharp's, Terry's, Green's and Westley-Richard's, and as a result of the opinions formed, and the example set by Prussia, committees were appointed in 1864 and 1866 by the British War Office, to report on breech-loading arms. In addition, gunmakers were invited to forward proposals for the conversion of the 1853 pattern Enfield rifle to the breech-loading method. Some 5o different suggestions for this conversion were investigated, and the one finally selected was that of Jacob Snider, an American, which was adopted in 1867.
Snider's conversion consisted of a breech block, hinged to swing up and out to the right. Through this block passed the firing pin, with which was a spring holding the pin to the rear so that its end protruded towards the hammer. When the hammer fell by pulling the trigger, it drove the pin forward so that its point struck the percussion cap. The block, when hinged down, was kept closed by a spring and cam action underneath. With the converted Enfield rifle was employed the cartridge invented by Col. Boxer. This cartridge was made up of coiled metal and had a percussion cap in the centre of its base. The advantage derived from this cartridge was that, under the gas pressure of the explosion, the cartridge expanded and so sealed the breech against escape of gas or flame ; also after dis charge the metal contracted, thus permitting simple and quick extraction of the case. In 1866 France adopted the bolt action Chassepot, used later in the Franco-German War. Shortly after wards, Sweden adopted the Hagstrom, Russia the Carte and Italy the Carcano rifles. All these were breech-loaders using paper cartridges containing their own means of ignition. The con version of the Enfield to the Snider was admittedly a temporary expedient, and soon after its completion steps were taken to procure a new design of rifle. Having received rifles from many different firms and factories, a model was selected which em bodied an action submitted by Martini, an American, as modified by the Royal Small Arms Factory, in combination with a barrel put forward by Henry, with which the Boxer cartridge was to be used. This was subsequently known as the Martini-Henry.