a popular choice of primary armament for armoured fighting vehicles manufactured around the world, such as Singapore's Bionix AFVs and as the Rafael Overhead Weapon Station-25 mounted on upgraded M113A2 Ultra IFVs. Enhanced 25 mm gun Work on an upgraded weapon began in 1990. In the upgrade program, all three major systems and seven minor systems were improved. The modifications began with introducing a chrome-lined barrel, an enhanced feeder, and an enhanced receiver. The weapon systems also received minor upgrades such as quick-detachable link covers, a larger breech assembly, a high efficiency muzzle brake, longer recoil, an integral round counter, an extended life firing pin and spring, and a triple-spring drive clutch. Upgraded weapons were first put to use on the M2A3 Bradley, the fourth version of the M2 Bradley Fighting Vehicle. Naval In 1977, the U. S. Navy realized that it needed a replacement for the Oerlikon 20mm Mk 16 series of guns. In 1986, this requirement was satisfied with the introduction of the Mk 38 Mod 0 weapons system. A derivative of the M242 system, the Mk 38 consists of the M242 chain gun and the Mk 88 Mod 0 machine gun mount. It provides ships with defensive and offensive gunfire capability for the engagement of a variety of surface targets. Designed primarily as a close-range defensive measure, it provides protection against patrol boats, floating mines, and various shore-based targets. Mk 38 Mod 2 and Mod 3 Recently, several US Navy platforms have been outfitted with a newer version, the Typhoon Weapon System designated Mk 38 Mod 2, which is remotely operated and includes an Electronic Optical Sight, Laser Range-Finder, FLIR, and a more reliable feeding system, enhancing the weapon system's capabilities and accuracy. In 2006 the Sri Lanka Navy added the M242 to its fleet of fast attack craft. The system is also in use by the Republic of Singapore Navy's s and s and were deployed as part of coalition forces' port security efforts in Iraq as well as anti-piracy roles in the Gulf of Aden. Aside from that, the Singapore Police Coast Guard's New Coastal Patrol Craft (NCPC) has adopted the system as its main armament. The Mod 3 updates electronics and adds a coaxial 7.62mm machine gun with a 570-round-per-minute rate of fire. Aselsan STOP Turkish made Aselsan STOP stabilized weapon station can be fitted with a M242 Bushmaster. BAE and Boeing teamed together