The L86 LSW (Light Support Weapon) was developed concurrently with the L85 IW (Individual Weapon) of the British Army. Both systems were adopted as standard issue weapons in the mid-1980s, seeing combat actions across the 1991 Persian Gulf War, the Balkans Wars and - more recently - in Afghanistan and Iraq. The L86 utilizes some 80% commonality of parts with the L85 assault rifle but is classified as a fire support weapon for squad-level engagements, offering accurate, ranged voluminous fire that outmatches that of the base L85 automatic weapon.
The L86 makes use of the same 5.56x45mm NATO cartridge of the L85 and operates from the same gas system. However, to coincide with its fire support role, the weapon is fielded with a longer, heavier barrel which increases muzzle velocity and, therefore, increases the cartridge's range and accuracy at range for engaging targets beyond the scope of the base L85 system. The barrel is furthermore fixed and not readily changeable. The L86 also features a rear vertical hand grip as well as a shorter handguard with lightweight bipod. The L86 does, however, retain the magazine-fed quality of the L85 and can accept its 30-round forms. A 60-round magazine is also available. The weapon can fire in semi-automatic mode or in full-automatic as the situation requires - the former through a closed breech and the latter holding the bolt by a rear sear. The SUSAT (Sight Unit, Small Arm, Trilux) optic is retained as standard.
The L86 initially debuted in the original L86A1 production form. These then gave way to the improved L86A2 variant which attempted to remedy the ongoing issues that proved disastrous to early L85/L86 units. The mid-life upgrade was handled by Heckler & Koch and occurred in the early 2000s.
The L86 in the squad support role has since given ground to the L110A1 (Fabrique Nationale FN Minimi), relegating the L86 to something more of a marksman's platform.