.223 most commonly refers to the .223 Remington catridge.

.223 may also refer to:

.223 MINISAS, a cartridge for close-quarter battle use .223 Winchester Super Short Magnum, a cartridge based on the Winchester Short Magnum case .223 Wylde chamber, a hybrid rifle chamber designed to allow .22 caliber barrels to safely fire either .223 Remington or 5.56×45mm NATO ammunition

See also

223 (disambiguation)