Chamber (firearms)

In firearms, the chamber is the portion of the barrel or firing cylinder in which the cartridge is inserted prior to being fired. Rifles and pistols generally have a single chamber in their barrels, while revolvers have multiple chambers in their cylinders and no chamber in their barrel. Thus rifles and pistols can be fired even with a detached magazine, while a revolver cannot be fired with its cylinder swung out.

The act of chambering a cartridge means the insertion of a round into the chamber, either manually or through the action of the weapon, e.g., pump-action, lever-action, bolt action, or automatic action.

In firearms design or modification, "chambering" is fitting a weapon for a particular caliber or round, so a Colt Model 1911 is chambered for .45 ACP or .38 Super, or re-chambered for .38/.45 Clerke.

See also

• Glossary of firearms terms