In 1850, regular British troops were still using flintlock Brown Bess muskets that had changed little since 1722, despite recent developments in detonation and expanding bullets. Pitt-Rivers, then Colonel Lane Fox, was appointed to a special committee set up to develop the army’s first a standard army service rifle. After collecting, deconstructing and experimenting with various models, Lane Fox commissioned this prototype gun, designed to fire Minié-Delvigne conical ammunition, which would ultimately be accepted by the British Army as the .577-calibre Pattern 1853 Enfield Rifle-Musket or ‘P53’.

The P53 retained the dimensions and muzzle-loading principle of the old musket, such as the long 39-inch barrel, partly to make it easier for troops to make the transition, but in contrast to the Bess it had a total of 56 parts. These included a three-grooved, 1:78 rifled barrel manufactured at the Royal Small Arms Factory at Enfield, and a percussion lock (here made by Wilkinson Sword, now better known for its razors).

The P53 was an era-defining weapon: the last powder-and-ball muzzle-loader, but the first mass-produced, service rifle. It was used in the Crimea (arguably helping the British and her allies to victory) and the Zulus used Belgian-made copies in the Anglo-Zulu War (1879). After 1867, many P53s were converted to Snider-Enfield cartridge rifles.

One of the most infamous episodes involving the P53 was its alleged role in the Indian Mutiny of 1857. The weapon, issued to imperial sepoys in the British East India Company Army, used self-contained cartridges consisting of a bullet and pre-measured amount of powder in a rolled paper tube – the thick paper used by artists is still referred to as 'cartridge paper' – which troops had to tear open with their teeth to pour down the muzzle. A rumour spread that the bullets were greased with pig fat or beef tallow. The concept of putting anything tainted with pig or beef fat near the mouth was unacceptable to both Muslim and Hindu sepoys on religious grounds. The reluctance of the British to deny the rumours, added to the British officers' indifference to the matter, let a volatile situation develop into outright rebellion.