The pepper-box revolver or simply pepperbox - from its resemblance to the household pepper grinder - is a multiple-barrel repeating firearm that has three or more barrels grouped around a central axis. It mostly appears in the form of a multi-shot handheld firearm. The pepperbox, at least the firearm that is mostly associated with this term, was invented in the 1830s and was intended for civilian use, but military officers often made private purchases for their own use.[3] The design spread rapidly in the United Kingdom, the USA and some parts of continental Europe. It was similar to the later revolver in that it contained bullets in separate chambers in a rotating cylinder. Unlike the revolver, however, each chamber had its own barrel, making a complex indexing system unnecessary.
A development from the pepperbox is the so-called "transitional" revolver. This weapon uses the same action but with one single barrel attached to the front of a cut-down pepperbox cylinder. It retained the pepperbox's caplock action but still had many deficiencies. The lack of an effective cylinder stop allowed a charge to be fired when the cylinder wasn’t aligned with the barrel, resulting in an erratic shot possibly damaging the gun and even injuring the firer. While the shortened cylinder made loading easier the barrel was attached to the cylinder pin; over time this weakened the gun, decreasing its accuracy. In addition it lacked partitions between its nipples, risking similar chain-fires to the earlier pepperbox.