For Internal Security use, the Federal Riot Gun being used in Northern Ireland for firing baton rounds and gas canisters was also adopted. The Bermudian reserve forces had been equipped with standard British Army weapons since their restoration in 1895 (although the Sten sub-machine gun had been replaced in the 1960s with the Israeli Uzi instead of the Sterling). A non-standard rifle was to replace the SLR, however. During the 1950s, the British forces had been pressured into dropping the .280 British sub-calibre round and EM-2 rifle that had been intended to replace respectively .303 inch ammunition and the No. 4 rifle, adopting instead the American 7.62mm ammunition as NATO standard and the SLR, which was a variant of the Belgian FN FAL. Despite forcing the adoption of the 7.62mm round by NATO, the US re-equipped during the Vietnam War with the M16 rifle, chambered for the 5.56×45mm M193 sub-calibre ammunition. Dissatisfaction with the 7.62mm round led NATO to seek a replacement during the 1970s, and the Belgian SS109 variant of the American M193 was adopted as 5.56mm NATO. Although it had also been intended to establish a NATO standard rifle, this did not materialise and different countries developed their own small arms. The Royal Small Arms Factory at Enfield Lock had actually begun work in 1969 on a family of weapons mechanically based on the ArmaLite AR-18, but chambered for a 4.85 × 49mm cartridge and with a bullpup configuration similar to the EM-2. This design was rechambered for the 5.56mm NATO and re-designated the SA80 ("Small Arms for the 1980s"). The family included two basic weapons: the XL64E5 rifle (also called the Enfield Individual Weapon) and a light support weapon known as the XL65E4 light machine gun (which were to be standardised as the L85A1 rifle and L86A1 Light-Support Weapon). The SA80 would remain stuck in development, however, until 1987, when the L85A1 and L86A1 began replacing respectively the SLR and the GPMG (together with the remaining Brens, which had been retained for jungle use and re-chambered for 7.62mm) in the British armed forces. Re-equipment was slow, and many second-line units were still equipped with the older weapons during the 1990 to 1991 Gulf War.