A rim-fire is a type of metallic cartridge used in firearms where the primer is located within a hollow circumferential rim protruding from the base of its casing. When fired, the gun's firing pin will strike and crush the rim against the edge of the barrel breech, sparking the primer compound within the rim, and in turn ignite the propellant within the case. Invented in 1845 by Louis-Nicolas Flobert, the first rimfire metallic cartridge was the .22 BB Cap cartridge, which consisted of a percussion cap with a bullet attached to the top. While many other different cartridge priming methods have been tried since the early 19th century, such as teat-fire and pinfire, only small caliber rimfire cartridges have survived to the present day with regular use. The .22 Long Rifle rimfire cartridge, introduced in 1887, is by far the most common ammunition found in the world today in terms of units manufactured and sold.

The pin-fire is a type of metallic cartridge used in firearms, where the priming compound is ignited by striking a small pin that protrudes radially from above the base of the cartridge. Invented by Frenchman Casimir Lefaucheux in 1832, but not patented until 1835, it was one of the earliest practical designs of a metallic cartridge to hasten the loading and firing process of a firearm. Its history is closely associated with the development of the breechloader, which would eventually replace all muzzle-loading firearms.