Caseless ammunition has been the small-arms ammunition of the future for decades now, but it was also the ammo of the future in the mid-1800s, before we settled on metallic cartridges:
Christian Sharps’ self-consuming cartridge made of linen was introduced in 1852. It was made at his Fairmount, Pennsylvania, gun factory. This was a definite improvement over the fragile paper-filled envelopes previously used. The linen could be held in shape and would stand more abuse than the paper cartridge. That cartridges, in one form or another, were beginning to be used throughout the service is verified by a record showing the purchase of 393,304 paper cartridges by the United States Army in 1851.
Col. Samuel Colt collaborated with the Ely brothers of England in making further improvements on his patented self-consuming cartridge. This cartridge was made of a stiffer and more durable paper, and could be held to close manufacturing tolerances. The paper cartridge case was impregnated with a mixture of potassium nitrate. The explosion of the powder charge completely consumed the cartridge case. The percussion cap had sufficient force to rupture the paper and drive fire through to the powder charge.
Smith and Wesson of Springfield, Mass., in 1857 manufactured the first really successful rim-fire version of a metallic cartridge, self-contained and reasonably waterproof. This ammunition, with added improvements, to the present day is still produced by various American companies.
On 22 January 1856, the unusual method of housing both detonator and propelling charge in the base of a bullet was introduced and patented. The Winchester Arms Co. made a repeating weapon called the “Volcanic” using this odd principle. As the propelling ingredients were all contained in the bullet itself, there was naturally no problem of case ejection. This radical design was to compete with the impregnated self-consuming paper cartridge cases.
The volcanic bullet had a small charge of finely granulated powder, and a larger portion of fulminate of mercury mixture housed in a thin metal cup, all of which was protected from the elements by a thin cork insert. When the ball was fed into the arm, a spring-loaded firing pin was cammed forward and forced through the cork until it was brought to bear on the primer cup. A smart blow from the hammer ignited the detonating mixture, forcing the flame through the openings provided, and exploded the powder in the upper conical cavity of the bullet.
During the middle of the nineteenth century, the introduction of various methods of producing cartridge cases, the development of the conical bullet, and the idea of integrating the detonating cap in the cartridge were undoubtedly responsible for the rapid and radical designs of the innumerable weapons constructed to fire them.
Even skin cartridge cases were used successfully. They not only furnished a waterproof container, but also were easily made into the self-consuming case that seemed to be a military “must” of the day. To produce this cartridge case, pig’s intestines were used. After cleaning and while still wet, they were stretched over forms of the required cartridge dimensions. When dried, the powder and bullet were put in place. The skin case was then treated with a compound consisting of “eighteen parts by weight of nitrate of potassium, pure, and seventeen parts of sulphuric acid — pure, after which it was washed to free it from the soluble salts and excess of acids, and then dried by blotting… in order to render it perfectly waterproof, a light coat of shellac varnish was applied.”
It is easy to see how multifiring weapon development went hand in hand with cartridge design. As each different type of cartridge was introduced, inventors followed closely with a mechanical firing system, designed to use the new idea. No matter how radical a departure any new cartridge may have been from the heretofore accepted methods, there was a gun with an equally original design to shoot it.
The greatest problem in ammunition development was finally solved by George W. Morse’s invention in 1858 — the first true attempt at a metallic cartridge with a center fire primer and an inside anvil. It marked the most important step in the whole history of cartridge design. All other methods, experiments, and alleged improvements were but attempts to do what Morse successfully accomplished.