The L86A1 LSW is magazine-fed automatic weapon originally intended to provide fire support at a fireteam level. It has a longer barrel than the L85A1 rifle and a bipod, shoulder trap and rear pistol grip, together with a shorter handguard. The extended barrel provides an increased muzzle velocity and further stabilizes the bullet, giving a greater effective range. The weapon is otherwise identical to the L85 version on which it is based, and the same 30-rd magazines and sighting systems are used. Like the L85 rifle, it has a rate-of-fire selector on the left side behind the magazine housing, enabling either single shots or automatic fire.
The increased barrel length, bipod and the optical performance of the SUSAT gives the weapon excellent accuracy. From its inception, the L86 was a target of criticism on much the same basis as the L85. The LSW has the additional issue (shared by any light support weapon derived from a rifle, for example the heavy-barrel FN FAL) of its inability to deliver sustained automatic fire as it does not have a quick-change barrel, and is not belt fed.
The primary use of the LSW has shifted to that of a marksman's weapon within many infantry sections, capable of providing extremely accurate precision fire at ranges of over 600m. The role of a light support weapon is instead filled with the L110 FN MINIMI which is a belt fed weapon with a quick-change barrel.
The L86A1 was upgraded to the L86A2 at the same time as L85A1 rifles were upgraded to L85A2 standards, undergoing the same set of modifications.