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.

A variant named L2A1/C2A1 (C2), meant to serve as a light machine gun in a support role, is also capable of fully automatic fire.

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.

Some Australian Army units deployed overseas on UN peacekeeping operations in Namibia, the Western Sahara, and Cambodia still used the L1A1 SLR and the M16A1 rifle throughout the early 1990s.

Australia, in co-ordination with Canada, developed a heavy-barrel version of the L1A1 as a fully automatic rifle variant, designated L2A1.

The L2A1 was similar to the FN FAL 50.41/42, but with a unique combined bipod-handguard and a receiver dust-cover mounted tangent rear sight from Canada.

Countries that embraced the heavy barrel FAL included Argentina, Australia, Belgium, Canada, and Israel.

[8] The Australians considered the strengths and limitations of the SLR and its heavy ammunition load to be better suited to actual combat.

Another product of Australian participation in the conflict in South-East Asia was the field modification of L1A1 and L2A1 rifles by the Special Air Service Regiment for better handling.

[6] For the L1A1, the lack of fully automatic fire resulted in the unofficial conversion of the L1A1 to full-auto capability by using lower receivers from the L2A1, which works by restricting trigger movement.

[12] Canada adopted the FAL in 1954, the first country in the world to actually ante up and order enough rifles for meaningful troop trials.

Up to this point, FN had been making these rifles in small test lots of ones and twos, each embodying changes and improvements over its predecessor.

Users could fold the trigger guard into the pistol grip, which allowed them to wear mitts when firing the weapon.

The Canadian rifle also had a shorter receiver cover than other Commonwealth variants to allow for refilling the magazine by charging it with stripper clips.

It was eventually phased out in favor of the lighter Diemaco C7, a licence-built copy of the M16, with a number of features borrowed from the A1, A2, and A3 variations of the AR platform assault rifle.

While a reliable and accurate weapon, the C2A1 was unpopular among Canadian soldiers due to its very limited sustained fire capability: the C2A1 lacked an interchangeable barrel, and its bottom-loading magazines were time-consuming to reload.

[19] It differs from the UK SLR in that the wooden butt-stock uses the butt-plate from the Lee–Enfield with trap[20] for oil bottle and cleaning pull-through.

[25] Production started in 1960 after the Armament Research & Development Establishment (ARDE) evaluated several Australian, Belgian and British FAL rifles and each one was disassembled and examined.

[26] Then Prime Minister Jawaharlal Nehru was not made aware of it and after he had heard it, offered to settle FN's complaints by agreeing to purchase additional Belgian-made FALs, FALOs and MAG 60.20 GPMGs.

The Ishapore 1A1, A and 1C is still in use by Central Armed Police Forces, some law enforcement bodies and also used during parades by the National Cadet Corps.

[30] An order for 15,000 L1A1 rifles was placed with the Lithgow Small Arms Factory in Australia which had been granted a license to produce the L1A1.

Other changes include: the introduction of a folding cocking handle; an enclosed slotted flash suppressor; folding rear sight; 'sand-cuts' modifications that provided space for limited sand or other dirt ingress into the upper receiver, bolt and bolt carrier; folding trigger guard to allow use with Arctic mitts; strengthened buttstock; enlarged change lever and magazine release catch; vertical stripping catch to prevent unintended activation; deletion of the automatic hold-open device and the addition of retaining tabs at the rear of the top cover to prevent forward movement of the top cover (and resulting loss of zero) when the L2A1 SUIT was fitted.

Initial production rifles were fitted with walnut furniture, consisting of the pistol grip, forward handguard, carrying handle and butt.

The Maranyl parts have a "pebbled" anti-slip texture along with a butt has a separate butt-pad, available in four lengths to allow the rifle to be fitted to individual users.

After the introduction of the Maranyl furniture, as extra supplies became available it was retrofitted to older rifles as they underwent scheduled maintenance.

[38] Despite the British, Australian and Canadian versions of the FAL being manufactured using machine tools which utilised the Imperial measurement system, they are all of the same basic dimensions.

Confusions over the differences has given rise to the terminology of "metric" and "inch" FAL rifles, which originated as a reference to the machine tools which produced them.

[37][42] Issued to the British Infantry, Royal Marines and RAF Regiment, the SUIT featured a prismatic offset design, which reduced the length of the sight and improved clearance around the action.

The aiming mark was an inverted, tapered perspex pillar ending in a point which could be illuminated by a tritium element for use in low light conditions.

[nb 1] The SLR was officially replaced in 1985 by the bullpup design L85A1 service rifle, firing the 5.56×45mm NATO cartridge.