L86A1 LSW

The L86A1 Light Support Weapon (LSW) was developed as part of the Small Arms for the 1980s (SA80) family to provide fire support at the fireteam level. Its design history traces back to the 1970s at the Royal Small Arms Factory, Enfield Lock, where it evolved from the XL65E4 light machine gun prototype. Initially chambered for an experimental British intermediate cartridge, the design was later modified to meet NATO standardization requirements as the XL73E3. The internal mechanism and sheet metal construction methods were influenced by the Armalite AR-18, while its bullpup configuration drew from earlier British experimental rifles such as the EM-2. Production transitioned to the Royal Ordnance facility in Nottingham in 1988 before concluding in 1994.

The L86A1 utilizes a short-stroke gas piston system located above the barrel, controlled by a three-position gas regulator. Its breech is locked by a rotating cylindrical bolt featuring seven radial locking splines. The receiver is constructed from stamped sheet steel, reinforced with welded and riveted machined steel inserts, while the furniture is fabricated from synthetic materials like nylon. As a bullpup-pattern weapon, the action is positioned behind the trigger group to maintain barrel length within a compact frame. To support its role as a squad automatic weapon, the L86A1 features a longer barrel than the standard rifle variant, an integrated bipod, a rear vertical grip, and a shoulder strap on the stock. The weapon is configured for right-handed operation because of the placement of the ejection port and reciprocating cocking handle.

Accepted into British service in 1985, the L86A1 was intended to replace the L4 Light Machine Gun and the L7A2 General Purpose Machine Gun at the section level. The weapon saw combat deployment during the Gulf War, where performance issues in sandy environments led to the A2 upgrade programme managed by Heckler & Koch starting in 2000. This modification focused on the bolt, extractor, and hammer assemblies to increase the average number of rounds fired between failures. Despite these improvements, the L86A2 was eventually supplemented by belt-fed machine guns for suppressive fire. Due to its accuracy in semi-automatic mode, the weapon's role shifted to that of a designated marksman rifle before its replacement by the L129A1. The L86 was officially withdrawn from British service in 2019, though it remains in use by Ministry of Defence-sponsored cadet organizations.