L1A1 Self-Loading Rifle

The L1A1 Self-Loading Rifle (SLR), also known by the initial Canadian designation C1, or in the U.S. as the "inch pattern" FAL (from French: Fusil Automatique Léger), is a British version of the Belgian FN FAL battle rifle. The L1A1 was produced under licence and adopted by the armed forces of the Commonwealth of Nations, mainly by United Kingdom, Australia, Canada, India, Jamaica, Malaysia, New Zealand, Rhodesia and Singapore.

The L1A1 is manufactured to a slightly modified design using British imperial units, not the metric units of the original Belgian FAL. Many sub-assemblies are interchangeable between the two types, while components of those sub-assemblies may not be compatible. Notable incompatibilities include the magazine and the stock.

Most Commonwealth pattern FALs are considered semi-automatic only, but they are not. On the L1A1s, the auto-sear, spring and connector were replaced with parts that prevented the L1A1 from firing until the bolt was fully locked. The receiver was machined to the same dimensions as a select-fire FAL, and if the auto-sear and parts are installed as they are in an FAL, the L1A1 will function as a select-fire weapon. A variant named L2A1/C2A1 (C2), meant to serve as an automatic rifle/light machine gun in a support role, was made capable of fully automatic fire from the manufacturer. Differences from the L1A1/C1 include a heavy barrel, squared front sight (versus the "V" on the semi-automatic models), a handguard that doubles as a foldable bipod, and a larger 30-round magazine although it could also use the normal 20-round magazines. Only Canada and Australia used this variant. Australia, New Zealand, and the United Kingdom used the Bren light machine guns converted to fire the 7.62×51mm NATO cartridge for use in the support role. Canadian C1s issued to naval vessels for boarding party usage were also capable of fully automatic fire.

The L1A1 and other inch-pattern derivatives trace their lineage back to the Allied Rifle Commission of the 1950s, whose intention was to introduce a single rifle and cartridge that would serve as standard issue for all NATO countries. They originally adopted the Rifle No. 9 Mk 1 chambered for a 7mm intermediate cartridge. To meet this plan and strengthen ties with the United States, the United Kingdom soon dropped the No.9 rifle in favor of the Belgian FAL chambered for the newly proposed American 7.62×51mm cartridge. Based on Canada's experiments with the FAL that led to the C1A1, the United Kingdom and Australia adopted the L1A1 (or Self-Loading Rifle) as their new service rifle in 1954.

NATO standardized on the 7.62mm NATO cartridge in 1954, but did not adopt a standard rifle. Most adopted a native design chambered for 7.62mm NATO, with Germany eventually adopting the G3 and the United States adopting the M14. Even the C1A1 and L1A1 used inch measurements and were not interchangeable with the FAL's metric parts. France's participation was to adopt a natively-designed service rifle that used their national 7.5mm MAS rifle cartridge.

The British experimental version of the FAL (designated the X-1) initially used an 8-round "horseshoe charger" (a U-shaped clip that held the cartridges) that was based on an experimental 10-round Belgian design. The operator would open the bolt and place the charger into guide rails over the chamber. The rounds would then be slid down into the detachable box magazine through the bolt. The 8-round horseshoe charger was replaced in trials with a 5-round model due to problems with them becoming damaged when packed in pouches or bandoliers. The 5-round horseshoe charger had similar problems and was replaced with an conventional straight 5-round charger.

The L1A1 subsequently served as the UK's first-line battle rifle up to the 1980s before being replaced by the 5.56mm L85A1.

The L1A1 and variants have seen use in several conflicts, including as part of the Cold War. L1A1s have been used by the British Armed Forces in Malaysia, Northern Ireland, and in the Falklands War (in opposition to FN FAL-armed Argentine forces), the First Gulf War (where it was still on issue to some second line British Army units and RAF personnel not yet issued with the L85A1), and by the State of Kuwait Army during the First Gulf War.