The U.K. has been active for many years with non-cured composite propellant, usually designed plastic propellant. There has also been considerable effort on castable systems which can be subsequently cured. Recently a hybrid type of propellant has been developed, which can be manufactured and extruded in a manner akin to plastic propellant, but cured later. This paper details the production methods used for both types of extrudable propellants. The particular advantages of the propellant are also discussed.