By the mid 1860s, the British had been using a rifle of the same basic pattern (with the proverbial lock, stock, and barrel) for over one hundred and forty years. The famous Brown Bess, having been largely supplanted by the 1853 Enfield, was obsolete, but the basic characteristics of a longarm remained. However, the late 19th Century heralded a time of rapid change, and the British military needed a new fast-firing breechloading rifle, and needed it fast. To meet this need, mechanisms were submitted that could convert existing 1853 pattern rifle-muskets to the new configuration, saving time and cost versus the adoption of a totally new weapon. The result was the Snider-Enfield, developed by an American small arms designer and consisting of a breech that was, by the standards of the day, a “drop-in” affair for the 1853 rifle-musket. The peerless channel britishmuzzleloaders takes a look at the Mark III Snider, the first of its type to be an entirely new-production weapon as opposed to a rifle-musket conversion:

The Snider-Enfield was the first breechloading rifle adopted by the British military, and would serve the regular army until it was phased out in favor of the newer small-caliber Martini-Henry beginning in 1874. With colonial forces, however, it would continue in service until the 20th Century.