Cordite is a family of smokeless propellants developed and produced in the United Kingdom from the late 19th Century to replace gunpowder as a military propellant for large weapons, such as tank guns, artillery and naval guns. Mark I Cordite was also used in the .303 British standard rifle cartridge between 1891 and 1915.
Cordite has been used since World War I by the UK and British Commonwealth countries. Its use was further developed in the early years of World War II, as 2 inch and 3-inch diameter solid-fuel rockets for launching anti-aircraft weapons. Small Cordite rocket charges were also developed for ejector seats made by the Martin-Baker Company.
Cordite is now obsolete and it is no longer produced. Production ceased in the United Kingdom, around the end of the 20th century, with the closure of the last World War II Cordite factory, ROF Bishopton. However, Cordite propellant may still be encountered in the form of legacy ammunition dating from World War II onwards.