The EM-2, also known as Rifle No.9 Mk1 or Janson rifle, which was an experimental British assault rifle.

It was briefly adopted by British forces in 1951, but the decision was overturned very shortly thereafter by Winston Churchill's incoming government in an effort to secure NATO standardisation of small arms and ammunition.

An innovative weapon with the compact bullpup layout and an optical sight, it used one of the early intermediate cartridges (a concept introduced by the Germans with the 7.92×33mm Kurz) as a result of combat experience and German advances in weapons design during World War II. As the EM-2 could not be easily adapted to the longer and more powerful 7.62×51mm NATO round, it faded from use. However, the bullpup layout for a British service rifle was finally adopted some years later in form of the SA80 assault rifle, the EM-2's spiritual successor, which remains in service today.

The XL60 series of experimental firearms was the first generation of what was initially known as the ‘485 Weapon System’, designed and produced at the Royal Small Arms Factory (RSAF) Enfield, located in North London, United Kingdom.

The term ‘485 Weapon System’, so-named for the weapon’s 4.85×49mm calibre, was later dropped in favour of ‘Enfield Weapon System’ or EWS, which persisted until at least 1982 but was ultimately also side-lined. Instead, the name ‘Small Arms of the 1980s’ or ‘SA80’ was adopted and remains in use to this day. This term is used alongside the land service or ‘L’ designations (e.g. L85A2). Interestingly, this name was in use from the very beginning by the Ministry of Defence (MoD), sometimes with the prefix ‘Section’ as in ‘infantry section’ or squad.

As per the preliminary study and MoD specification, the EWS/SA80 system comprised rifle and light machine gun variants, known by their period NATO euphemisms of ‘Individual Weapon’ or IW for short (today simply ‘Rifle, 5.56mm’) and ‘Light Support Weapon’ or LSW (a term still in use today, sometimes considered interchangeable or overlapping with ‘squad automatic weapon’, or SAW; automatic rifle; and light machine gun, or LMG). Several variants emerged during development which all received their own designations.

SA80 (L85A2) is the personal weapon system used by British Land, Sea and Air Forces. On its introduction, it proved so accurate that the Army marksmanship tests had to be redesigned.

SA80 A2 comprises the Individual Weapon (IW) and the Light Support Weapon (LSW).

These are the British Army's standard combat weapons. Made by Heckler and Koch, they fire NATO standard 5.56 x 45mm ammunition. Other attachments including the L123A1 40mm Underslung Grenade Launcher (UGL) and forward grips. Both weapons have been modified in light of operational experience. A major mid-life update in 2002 resulted in the SA80A2 series - the most reliable weapons of their type in the world. This reliability is combined with accuracy, versatility and ergonomic design. It is considered a first-class weapon system and world leader in small arms.

• Organization: MOD
• Object Name: DDC-17-144-056
• Supplemental Categories: EM-2, Guns, Weapons, Equipment, XL 60, SA80
• Keywords: Historic Weapon, EM-2, Equipment, Weapons, Gun, Firearm, Small Arms, Assault Rifle, SA80, Army
• Country: UK