After British participation in World War 2 (1939-1945) had ended, thought was given to modernizing Army infantry with a new standardized automatic weapon. This gave rise to the EM-1 and EM-2 prototype rifles which centered around a 7mm cartridge and arranged in a "bullpup" configuration with the action residing aft of the trigger group. However, NATO acceptance of the 7.62x51mm cartridge forced an end to the British endeavor to which the Army then settled on the L1A1 Battle Rifle, itself nothing more than a license-production variant of the Belgian FN FAL Battle Rifle. The L1A1 began service in 1954 and saw combat in several notable conflicts involving the British military including the Suez Crisis, the Malayan Emergency and the Falklands War. The type was produced into the 1980s and saw service into the 1990s while also be adopted by Australia and Canada (as the C1A1 SLR).
In 1969, the storied facility at Enfield Lock experimented with a new 4.85x49mm cartridge to coincide with a development of a new family of automatic weapons for possible adoption by the British military. A bullpup-configured rifle design was established to fire the cartridge while the family of firearms was collectively known under the "SA80" designation. This work produced the "XL64EF" automatic rifle and the "XL65E4 LMG" (Light Machine Gun). Both designs were similar in most respects to one another which made for a logistically-friendly approach. The assault rifle would be fielded by the bulk of British infantry while the light support weapon would be given to select units intended for fire support of the main squad. Prototypes were available for trails in 1976.
Once again, NATO standardization of the American 5.56x45mm cartridge forced a change to evolving British plans. Thusly, SA80 prototypes were revised internally to fire the slightly larger round, this producing the "XL70E3" automatic rifle and the corresponding "XL73E3 LSW". Both of these designs then evolved to become their respective finalized prototype forms as the "XL85" and "XL86". In turn, these were then adopted for service in the British Army inventory as the "L85 IW" (Individual Weapon) and "L86 LSW" (Light Support Weapon), the former selected to replace the venerable L1A1. Initial deliveries of L85s began in 1985 with production handled by the Royal Small Arms Factory at Enfield Lock. In 1988, production was relocated to the Royal Ordnance's Nottingham Small Arms Facility which later came under the brand labeling of BAe Systems Land Systems Munitions. All production completed in 1994 to which over 350,000 units were delivered. The weapon went on to see adoption by forces in Bolivia, Jamaica and Sierra Leone.
The key design quality of the L85 was its bullpup configuration which currently remains a growing approach to most frontline automatic weapons today. In such a configuration, the primary internal elements of the weapon - the action and feed - are located to the rear of the trigger group. This allows use of a full-length barrel within a more compact form, thus retaining the needed robust qualities of an automatic assault weapon. The forend is, therefore, shortened as a result and the bulk of the weapon's weight now resides to the rear of the gun, firmly pressed against the operator's shoulder. There are two schools of thought concerning use of bullpup-configured weapons - those that cite increased accuracy and quicker response times when engaging in close-quarters affairs and those who prefer the tried-and-true nature of traditionally-arranged assault weapons. Two notable drawbacks of the bullpup design are the close location of the ejection port to the firer's face and the shortened forend which can see the operator accidentally move his hand ahead of the muzzle when firing. In relation to the first concern, the location of the ejection port also limits the weapon to favor right-handed shooters and makes an ambidextrous design impossible.
At its core, the L85 remains an effective gas-operated weapon chambered for the 5.56x45mm NATO cartridge. The internal action utilizes a rotating bolt and features a rate-of-fire of 775 rounds-per-minute. The system incorporates a traditional gas piston which drives a bolt carrier riding two bolts with return springs. The receiver makes up the shoulder stock portion of the weapon and features a charging handle set to the right side - requiring the operator to reach over the receiver with his support hand. Magazines are inserted into the base of the receiver behind the pistol grip. The pistol grip is centered under the length of the design with a handguard-forend affixed ahead. The barrel is partially shrouded by the handguard and protrudes a short distance away from the weapon while being capped by a slotted flash suppressor. A standard optics system (SUSAT = Sight Unit, Small Arm, Trilux) is affixed over the receiver in the usual way while aperture iron sights are also provided. Muzzle velocity is 3,100 feet per second while the weapon is fed from a 30-round STANAG type magazine. Effective range against a single defined target body is approximately 400 meters. The firing action is selective while the rifle's body can accept the standard British Army bayonet. Primary construction of all working parts and those expecting battlefield abuse are of steel with plastic used in the furniture.