Definition: "Rimfire" refers to a metallic cartridge which contains priming compound within its rim, rather than in a separate primer. This compound is sort of sandwiched between two layers of brass around the rim, and when the firing pin strikes the cartridge rim, it rapidly compresses the priming compound. This causes the compound to create a spark inside the cartridge case, which in turn ignites the powder charge, propelling the bullet through the gun's barrel and beyond.
Many types of guns have been made to fire rimfire cartridges, including bolt action, semi-automatic, and single shot rifles, as well as handguns of many varieties, both revolvers and pistols. The most popular rimfire cartridge by far is the 22 Long Rifle (22LR).
Pronunciation: Rim fire (adjective)
Alternate Spellings: Rim Fire
Examples: The 22 Long Rifle is the most popular rimfire cartridge in the world.
