Westley Richards is a British manufacturer of guns and rifles and also a well established gunsmith. The company was founded in 1812 by William Westley Richards, who was responsible for the early innovation of many rifles used in wars featuring the British Army during the 1800s. It remained in the hands of the Richards family until it was purchased by Walter Clode in 1957. Currently the company has two listed directors, Alexander Clode and Sheikh Sultan Bin Jassim Al Thani of Qatar. The company has received a number of royal warrants since 1840.

The percussion cap, percussion primer, or caplock, introduced in the early 1820s, is a type of single-use percussion ignition device for muzzle loader firearm locks enabling them to fire reliably in any weather condition. Its invention gave rise to the caplock mechanism or percussion lock system which used percussion caps struck by the hammer to set off the gunpowder charge in rifles and cap and ball firearms. Any firearm using a caplock mechanism is a percussion gun. Any long gun with a cap-lock mechanism and rifled barrel is a percussion rifle. Cap and ball describes cap-lock firearms discharging a single bore-diameter spherical bullet with each shot.