M30 (4.2-inch / Four-Deuce)

1951 COLD WAR KOREAN WAR MODERN VIETNAM WAR

• 1 M30 (4.2"/Siping) History
• 2 M30 (4.2 inch / Four-Deuce) Specification
  • 2.1 Roles
  • 2.2 Dimensions
  • 2.3 Performance
  • 2.4 Changes

M30 (4.2"/Siping) History

Mortar weapon systems have been in use for decades and have proven themselves time and time again in the field of indirect fire. This weapon proved vital in the offensives of both world wars and is still on display today in every major army.

The challenge for war planners has always been to provide a man-portable mortar system suitable for infantry use, which ultimately dictated the design and inherent limitations.

During World War II, the U.S. military heavily suppressed enemy positions with 4.2-inch M2 mortars. The system was in operation from 1943 to 1974. In the 1950s, a newer, more modern weapon was considered, the design of which was based on the practical experience of World War II aircrews.

This 1951 entry later became the M30 4.2".

Both systems have a caliber of 106.7 mm (107 mm), but the new model has a longer range and higher accuracy. The final product became a 5-foot-long, 670-pound system.

A typical crew for a normal job is 5 people, and due to the size and weight of the weapon, it is traditionally mounted on and launched from a delivery vehicle such as the M113 Armored Personnel Carrier (APC).

The design of the M30 fell to the US Chemical Warfare Service. Both the early M2 and the newer M30 were called "Four-Deuce" because of their caliber in inches (4.2). The M30 is still serving a handful of operators, including Brazil, Greece, the Philippines and Saudi Arabia.

The structural layout of the M30 is typical of a mortar weapon, as the configuration relies on a simple launch tube, base plate, support structure, and integrated aiming device. It fires three different projectiles in five forms, including two HE (High Explosive) types (HE M329A1 and HE M329A2), one WP (White Phosphorus) projectile (WP M328A1) and two long-range illumination projectiles (ILLUM) M325A2 and ILLUM M335A2) 5,500 meters or more. The rate of fire is as high as eighteen rounds per minute, or three bursts. The absolute maximum range is 6,850 meters.

Controls on the mounting hardware support arm allow the operator to influence the elevation and roll functions of the weapon.

The M30 series served in the Korean War (1950-1953) and the Vietnam War (1955-1975).

M30 (4.2 inch / Four-Deuce) Specification

Roles

Dimensions

Performance

Changes