M242 Bushmaster

M242 Bushmaster. The M242 Bushmaster is a 25 mm (25×137mm) single-barrel chain-driven autocannon developed in the late 1970s and entering U.S. military service in the early 1980s. Designed primarily as a vehicle-mounted weapon, it provides substantial firepower against light armored vehicles, infantry, and low-flying aircraft. Its adoption marked a significant increase in the organic firepower of American Army and Marine Corps armored reconnaissance and infantry fighting vehicles.

Development and history

The development of the M242 was initiated by the United States Army Armament Research and Development Command in the 1970s to fulfill a requirement for a new medium-caliber automatic cannon. The contract for its design and production was awarded to the Armament Systems Division of McDonnell Douglas, leveraging technology from the earlier M139 cannon. Key design goals included high reliability, dual-rate-of-fire capability, and safety in confined vehicle spaces. The weapon successfully completed its Operational Test and Evaluation and was type-classified in 1981, with initial fielding on the M2 Bradley and M3 Bradley fighting vehicles. Subsequent production and support contracts have been managed by Alliant Techsystems and later BAE Systems.

Design and features

The M242 is an externally powered, chain-driven autocannon, a system where a reversible electric motor drives a roller chain to cycle the weapon's mechanism. This design allows for precise control over the rate of fire, with selectable high (500 rounds per minute) and low (200 rounds per minute) settings. It fires the standardized 25×137mm NATO cartridge, fed from dual disintegrating link belts that permit immediate selection between armor-piercing discarding sabot (APDS), high-explosive incendiary (HEI), and high-explosive incendiary/armor-piercing (HEIAP) rounds. The gun features a floating recoil system to minimize mounting stress and includes a comprehensive safety system with a last-round bolt hold-open device.

Operational use

The M242 has been the primary armament for several key U.S. and allied platforms, most notably the M2 Bradley and M3 Bradley family of vehicles. It is also integral to the LAV-25 used by the United States Marine Corps and has been fitted to various naval craft, including the Mark 38 Mod 2 Machine Gun System for force protection aboard U.S. Navy ships. The cannon saw extensive combat use during the Gulf War, the Iraq War, and the War in Afghanistan, proving effective against Iraqi Army vehicles and fortified positions. Numerous other countries, including Canada, Australia, and Saudi Arabia, employ the M242 on their own armored vehicles and naval platforms.

Variants

The primary variant is the baseline M242, with the M242E6 being a lightweight model developed for the Expeditionary Fighting Vehicle program. The Mk 38 Mod 2 is a stabilized naval mount system incorporating the M242, used for surface defense. The Bushmaster II and Bushmaster III are evolutionary, higher-caliber designs (30mm and 35mm/50mm respectively) developed from the M242's core chain-gun principle by BAE Systems. Various specialized mounts and feed system adaptations have been created for integration into different vehicle turrets and stationary defensive positions.

Specifications

* **Caliber:** 25 mm (25×137mm NATO) * **Operation:** Externally powered, chain-driven * **Weight:** 119 kg (262 lb) * **Length:** 2.99 m (9 ft 10 in) * **Barrel Length:** 2.44 m (8 ft) * **Muzzle Velocity:** 1,100 m/s (3,600 ft/s) (APDS) * **Rate of Fire:** 200 rpm (low), 500 rpm (high) * **Effective Range:** 2,000 m (ground targets), 1,500 m (air targets) * **Feed System:** Dual disintegrating link belt * **Ammunition Types:** APDS, HEI, HEI-T, HEIAP, TP

Category:Autocannons Category:25 mm artillery Category:Vehicle-mounted guns