A speedloader is a device used to reduce the time and/or effort needed to reload a firearm. Speed loaders come in variety of forms for reloading revolvers or with fixed (attached) or detachable magazines.
Generally, speedloaders are used for loading all chambers of a revolver simultaneously, although speedloaders (of different designs) are also used for the loading of fixed tubular magazines of shotguns and rifles, or (with other designs) the loading of box or drum magazines. Revolver speedloaders are used for revolvers having either swing-out cylinders or top-break cylinders. Non-top-break cylinder revolvers having fixed cylinders must be unloaded and loaded one chamber at a time.
The modern revolver circular speedloader holds a full cylinder complement of cartridges in a secure fashion, spaced in a circular configuration so as to allow the cartridges to drop simultaneously into the cylinder easily (although non-circular types such as half-moon clips are very common as well). A mechanism is provided that allows the cartridges to be released from the speedloader when loaded, so that when it is removed, the cartridges remain in the cylinder. The most common type of speedloader uses a rotating latch. Another type slides the cartridges out an open side; and a third type has a latch that releases when pressed.
Revolver speedloaders make the process of reloading an appropriately matched revolver much faster than reloading one round at a time (provided you have ready-loaded speedloaders available). Swing-out and top-break revolvers are designed to eject all cartridges with one movement, and speed loaders allow loading with but a single additional step. Speedloaders also provide a convenient way to carry ammunition for a revolver. Speedloaders do not, however, allow revolvers to be reloaded as fast as semiautomatic handguns without considerably more practice.
Prior to the introduction of speedloaders for revolvers, reloading of revolvers was always accomplished by manually loading each cartridge into each chamber from cartridge loops on a belt or bandolier, a cartridge pouch, or other cartridge holder, such as a pocket. In fact, hand-loading is still the most common way of loading a revolver, speedloaders being mostly restricted to competition shooters and those who feel that they need more firepower for their personal defense revolver, since although speedloaders are useful for carrying one or several reloads at ready, one must load the speedloaders themselves prior to using.