The L64 was an intermediate calibre British bullpup layout prototype assault rifle developed in the 1970s. At one time it was known as the 4.85 Individual Weapon, a reference to the calibre of the bullet it fired. The Royal Small Arms Factory developed a rifle to fire the new round. The new L64/65 "Individual Weapon" was outwardly similar to the earlier EM-2, but adopted a firing mechanism very similar to ArmaLite's latest AR-18 design. The first examples were available in 1972. The L64 pattern was later developed into the SA80 family of weapons, which entered service with the UK in the 1980s.