The SA80 (Small Arms of the 1980s) is the standard issue British Army rifle (Its two versions are designated as L85 and L86, which are respectively infantry rifle and light support weapon.). It is also used by other branches of the British armed forces per necessity, as well as Jamaican Defense Force. There is also an even shorter carbine variant used by Helicopter/Tank crews and Royal Marine boarding parties known as the L22A1/L22A2. The SA80 components were notoriously "copied" by Enfield Workers from the SAR-87 manufactured by Sterling Armaments at the same time but this led to the notorious unreliability of the L85A1.
SA80 is of the bullpup configuration. It has a simple fire selector with two settings: (single/auto). The SA80 is compatible with any STANAG magazine. It is fitted with a bayonet lug. Full-sized versions of SA80 can be fitted with AG36 underbarrel grenade launcher (which reportedly enhances the somewhat poor balance of the weapon).
All SA80 rifles are equipped with SUSAT sights upon shipping. According to operator reports, SUSAT tritium sights are one of the best features of this firearm. Alternatively, the SA80 is equipped with a bladed front sight, and a diopter rear sight that also functions as a built in carrying handle - this configuration is usually used by second-line troops. However it must be noted that this weapon performs very well in CQB situations as it can be brought up to the sight line easily and quickly, which is useful when the urban nature of a battle means shots have to be taken in seconds.
Some reports of component failure in the original design have been noted, such as the cocking handle falling off, rendering the weapon useless or other bits and pieces to come loose. Another problem is that the SA80 is heavier than many other 5.56x45mm NATO rifles. Of particular annoyance was the habit of the magazine of A1 variants to fall out of the rifle when held across the chest due to the location of the release. British soldiers have, on occasion in the past, demanded alternate weapons such as the G36 or weapons of the M16 family. There was been some speculation that the UK would replace the SA80 with the G36 or a similar weapon, but this was dispelled by the improvement programme undertaken by H&K (which updated almost all rifles to the improved A2 variant) which solved most issues and has made the rifle into one of the most reliable weapon systems in the world.
The immediate background to the SA80 lies in the decision in the late 1960s, to start looking for a replacement for the L1A1 SLR. The 7.62x51mm NATO cartridge that it fired had always been considered overpowered by the British, even though it was designed as a compromise between the American .30-06 cartridge and the British .280 round. The nature of the compromise meant it was little more than a .30-06 cartridge with a shorter case and the round therefore fell between the two camps, that is, it was not quite as powerful as the rounds it replaced but too powerful to be a practical assault rifle cartridge. NATO adopted it in 1954 and the British, having been forced to adopt it and keep the cartridge and the rifle that fired it in service for what would turn out to be three decades, decided that next time, the decision would be based on firm technical and tactical requirements. Or so they thought. Once again, the British looked at data from both world wars and Korea but by this time could include data from the war in Vietnam. They decided that any future ammunition requirement would be based on the theoretical maximum engagement range that came out of an analysis of this data, which turned out to be around 400m.
Enfield 4.85mm Individual WeaponEdit
The foundations for what would eventually become the Enfield Weapon System (EWS) were laid in the early 1970s. In 1970, the Director General Weapons (Army) asked Royal Small Arms Factory, Enfield to conduct a study, to be finished by the end of 1971, with the following objectives:
- To define what sort of target a future weapon should be able to hit and what criteria should be set out that would constitute defeating said target;
- To assess a range of ammunition calibres, ranging from 4mm to 7.62mm with regard to an effective range of between 400 and 600m;
- To look at a variety of weapon configurations with regard to a requirement that it be lighter than the current standard weapon and easier to handle;
- To investigate the possibility of incorporating an area-effect capability (for example, a rifle grenade);
- To investigate what was happening world-wide, with regard to the design and procurement of small arms.
RSAF Enfield reported back in December 1971 with the following findings: The size of the target was determined as being 450mm x 900 mm (approximately 18in x 35in) and the criteria as being an energy of 466j, that being necessary to defeat the best steel helmet then in use (West Germany);
- An optimum calibre of around 5mm for both an Individual Weapon (IW) and a Light Support Weapon (LSW);
- It was unlikely that unconventional systems (such as caseless ammunition or flechette projectiles) would be able to be developed adequately in the timeframe stipulated so a conventional cartridge was recommended;
- There were no definite conclusions as to how best to incorporate an area-effect capability, although a grenade launched from the weapon's muzzle was considered preferable;
- Most small arms manufacturers were utilising advances in materials and technology to improve weapon handling, reduce weight and even offer unconventional solutions.
RSAF Enfield then looked at the system configuration, and came to the conclusion that:
- Both the IW and LSW should be of an unorthodox configuration with a straight butt, which would give a shorter overall weapon, save weight and improve handling;
- It be of around 5mm in calibre;
- Both be able to fire accurately out to about 600m;
- The commonality of components be as high as possible;
- It be capable of both semi-automatic and fully-automatic fire;
- It be gas operated;
- It have a multi-lug breech-operating system;
- It be fitted with an optical sight similar to the SUIT on the L1A1;
- If possible, the weapon would have a three-round burst limiter included;
- It have a cyclic rate of between 300 and 1,000 rounds per minute;
- The prototype LSW use a combined open / closed bolt operation – this would improve reliability and lower the chances of a 'cook-off' after fully automatic fire but mean a more complicated mechanism and lower commonality of components.
The result of this preliminary work was General Staff Target (GST) 3815, published in 1972. This document concentrated the project's future direction and laid down guidelines to be followed during the next two years of feasibility work. These guidelines were:
- The weapons would be in 4.85mm calibre, keeping the LSW as light as possible at the expense of having the IW fire a round that was slightly more powerful than optimum;
- The weapons are as light as possible, in a bullpup configuration and be adaptable to either left or right-handed use by a unit's Armourer;
- The weapons would have an optical sight that was as good as or better than the SUIT;
- They would be capable of accepting a night sight;
- Further research into the possibility of having an area-effect capability would be undertaken;
- Definite designs would be produced.
13 years later Enfield started work on the L85A1 rifle and it was soon being mass-produced and issued
- XL64 IW - An experimental 4.85mm-calibre assault rifle that was prototyped in the mid-1960s at Enfield. It took some design cues from the earlier EM-2 rifle and the ArmaLite AR-18. The XL64 project was cancelled, mainly because the 4.85mm calibre was overshadowed by 5.56 ammunition.
- XL65 LSW - The light machine gun variant of the XL64 IW. It was scrapped along with the XL64 when NATO opted for 5.56 ammunition rather than 4.85mm.
- XL70E3 - Enfield tried again to produce a bullpup service rifle after the failure of the 4.85mm cartridge. In the 1970's, they produced the XL70E3. The XL70E3 was very similar to the XL64 IW, but re-chambered for 5.56 ammunition to meet the demands of NATO. Design issues meant that it needed more time to be improved, resulting in the birth of the SA80, or L85A1 service rifle.
- XL73E2 - The light machine gun variant of the XL70E3. It was improved upon in later years and the final product was the L86 Light Support Weapon.
No longer in use except with some reserve units, the original variant of the SA80. Reports from operators indicate, that this firearm, while possessing unusual precision for an assault rifle, had serious problems with reliability, especially during automatic fire, and was very sensitive to fouling and handling, due to being converted to semi-automatic for use by Cadets.
This modification had been adapted in 1997, and most of the L85A1s were upgraded to the L85A2 configuration throughout 2000-2002. In this modification most of the original problems (many discovered during the first Gulf War) were addressed. Some features include Teflon coated gas parts and bolt carrier to prevent carbon buildup, upgraded magazine receiver and an ergonomically shaped cocking handle. L85A2s have accommodation for easy installation of the AG36 grenade launcher. During an international test the L85A2 was proven to be the most reliable service rifle in the world, firing around 65000 rounds without a single problem, beating such weapons as the M16, Steyr AUG and G36 in reliability by a long way. The L85A2 has recently been issued with a RIS. It has also been issued with an ACOG scope as a UOR for operations in Afghanistan. Please note that reliability is suggestive, and has more to due with maintenance than anything else.
It should be noted that at the time of retrofitting H&K were owned by RO (Royal Ordinance) as it's parent company, resulting in much of the British Press's criticism of a "government" domestic rifle needing to be fixed by a foreign corporation was moot, as RO was and still is, owned by BAE Systems (With RO now BAE Systems Global Combat Systems Munitions).
This did not however prevent the national embarrassment over the fiasco of the A1, nor the retrofitting as Neither HM's Government nor BAE Systems highlighted the mistake. 
H&K were sold in 2002 by BAE to private owners.
The so-called A3 version is not in fact an A3 as in order for the MOD to increase the A# Designation of a weapon, it generally requires tooling, or some other change to the rifle itself rather than the attachments thereon.
However, these upgrades include:
Laser Light Module Mk3 Laser Sight range of 800m
A new Acog x4 with integrated mini red-dot sight for CQB
Possible upgrade of USGL, with the possibility of shotgun shell type ammo for CQB
Vortex Flash hider
New barrel shroud to permit RIS rails
and a Grip-pod. 
L98A1 Cadet GPEdit
Previously issued to cadet units but has now been completely phased out. It is not capable of automatic fire and has to be manually cycled for every shot. Different from the L85A1 by being shorter, lighter due to a lack of gas parts, and a cocking handle extender to aid reloading for younger cadets.
L98A2 Cadet GPEdit
New issue to cadets it is a semi automatic rifle the only difference between the L98A2 and the L85A2 is barrel length and a missing change lever.
There have been three attempts at a carbine. The first was in 1989 (length overall 556mm, barrel length 289mm). The second attempt was in 1994; this used the standard L86 LSW handguard and a 17.4 inch barrel (length overall 709mm, barrel length 442mm). The third attempt (2003–2004) is also the only one to officially be adopted - the L22. This resembles the '89 model but has all the necessary A2 upgrades, it has a 318mm (12.5") barrel and an overall length of 585mm. Around 1,500 were "manufactured" from surplus L86 LSW's, more were built with the increased demand. Due to the shortened barrel (12.5"), it is less accurate and less powerful, especially at long ranges. Because there is no handguard, these guns are outfitted with a vertical front grip. (Exists in A1 and A2 variants). Initally issued to tank and armoured vehicle crews for emergency action out of vehicle, the L22 has been seen in the hands of the Royal Marines Fleet Protection Group and Army Air Corps Apache and Lynx aircrews due to the compact size
This version of the SA80 was initially intended as the infantry light support weapon. It features a longer and heavier barrel, underbarrel rail with folding bipods and vertical grip behind the magazine housing. Due to its design as an LSW, it can`t mount a bayonet, or a grenade launcher. In practice, the L86 had proven to be poorly suited for a support weapon role because of its limited magazine capacity, fixed barrel (weapons intended for this role must, as a rule, be able to swap barrels quickly) and general reliability problems in full-automatic fire, therefore making it somewhat useless for its role. However, its excellent single-shot accuracy allows it to be successfully used as a marksman rifle. The L86 is usually used as such, and is currently known as a DMR (Designated Marksman Rifle). For suppression fire, the British Army now issues the FN Minimi SSW as of late.
SA80B Police CarbineEdit
A variant intended for use with the Metropolitan Police force. It features an optical sight on top of the carrying handle and a large underbarreled flashlight. This variant has also seen limited service with special forces.