×
Aircraft / Aviation Vehicles & Artillery Infantry Arms Warships & Submarines Military Pay Scale Military Ranks
Advertisements
HOME
INFANTRY
MODERN ARMIES
SPECIAL FORCES
COUNTRIES
MANUFACTURERS
COMPARE
BY CONFLICT
BY TYPE
BY DECADE
COLD WAR

M31 HEAT


Anti-Tank (AT) Rifle Grenade (1957)


Infantry Small Arms / The Warfighter

1 / 1
Image from official US Army training material.

Jump-to: Specifications

The M31 HEAT anti-tank rifle grenade was adopted by the United States military as a replacement for the Korean War-era ENERGA series originating in Belgium.



Authored By: Staff Writer | Last Edited: 08/15/2017 | Content ©www.MilitaryFactory.com | The following text is exclusive to this site.
Advertisements
While under experimentation by the Japanese as early as 1904-1905, the rifle grenade came into its own with the French during World War 1 (1914-1918). The rifle grenade broadened infantry-level firepower by allowing a standard service rifle to accept and fire a grenade projectile, adding range and lethality to the foot soldier's reach. Many rifle grenade designs soon emerged from various global parties and their use continued into World War 2 (1939-1945) and further. By the time of the Korean War (1950-1953), American forces had taken on the Belgian "ENERGA" series (detailed elsewhere on this site) but this was only intended as an interim move for an all-new indigenous rifle grenade design was already in the works - the M31 HEAT ("High-Explosive, Anti-Tank").

The M31 bettered the ENERGA by reducing internal complexity and overall weight while increasing battlefield performance and reliability. Design work began during the mid-to-latter part of the 1950s and this led to serial production beginning before the end of the decade. Its battlefield use primarily covered the anti-tank role but the grenade also held some value against infantry. Effective engagement ranges reached 115 meters while maximum ranges peaked at 185 meters from the shooter's position.
Advertisements
Overall weight was 709 grams with an overall length measuring 430mm. The projectile held a diameter of 66mm at its warhead. Its general shape was of a rocket and fins were used to stabilize the unit while in flight. Detonation was through a nose-actuated, base detonation arrangement relying in a piezoelectric fuze. The nose cap of the projectile held the piezoelectric crystal to which a lead wire was attached. This ran down to the fuze located at the base of the warhead. The forward section of the warhead was hollow so as to collapse upon impacting a surface. 254 grams of Composition B filling were used for detonation and engagement angles reached 65 degrees. A mechanical safety system was in play to prevent accidental detonation of the weapon during transport and handling.

The standard service rifle for American forces after the Korean War was still the classic M1 Garand of World War 2 fame so the M31 was designed with the Garand in mind and coupled with the M7A3 launcher. When the M14 semi-automatic rifle became the next American standard, the M31 was modified for use with this weapon system and brought along support for the M76 series launcher instead. In either case, the adapter was fitted directly to the muzzle of the rifle component and the grenade actuated through use of the M3 ballistic cartridge - these rounds specific to rifle grenade-launching in the American inventory. The projectile simply sat atop the launcher unit through its hollowed-out base.

The M31 only ever proved consistently effective against light armored vehicles and other "soft" targets as success was greatly reduced against the protection of a heavy tank. This led to the adoption of more potent man-portable systems such as the shoulder-fired M72 LAW (Light, Anti-Tank Weapon) which went on to replace the M31 in service with the American Army and Marine forces. The M31 continued to see service in the Vietnam War (1955-1975) but, by the end of the conflict, was given up for good. Many other global frontline forces moved in the direction of more potent, shoulder-fired weapons as well, leaving few today that still rely on some form of rifle-launched grenade projectile. The anti-infantry role of the rifle grenade was taken up by single- or multi-shot grenade launchers.

Specifications



Service Year
1957

Origin
United States national flag graphic
United States

Classification


Anti-Tank (AT) Rifle Grenade


State Factories - USA
National flag of the United States United States
(OPERATORS list includes past, present, and future operators when applicable)
Anti-Armor / Anti-Tank / Anti-Material
Designed to engage and defeat armor / enemy tanks at range.


Overall Length
430 mm
16.93 in
Barrel Length
430 mm
16.93 in
Empty Wgt
1.56 lb
0.71 kg
Sights


Not Applicable.


Action


Single-Use; Impact Detonated

(Material presented above is for historical and entertainment value and should not be construed as usable for hardware restoration, maintenance, or general operation - always consult official manufacturer sources for such information)


Caliber(s)*


66mm

Rounds / Feed


Single-Use
Cartridge relative size chart
*May not represent an exhuastive list; calibers are model-specific dependent, always consult official manufacturer sources.
**Graphics not to actual size; not all cartridges may be represented visually; graphics intended for general reference only.
Max Eff.Range
377 ft
(115 m | 126 yd)


M31 - Base Series Designation


Military lapel ribbon for the American Civil War
Military lapel ribbon for pioneering aircraft
Military lapel ribbon for the Cold War
Military lapel ribbon for the Falklands War
Military lapel ribbon for the Korean War
Military lapel ribbon representing modern aircraft
Military lapel ribbon for the Vietnam War
Military lapel ribbon for the World War 1
Military lapel ribbon for the World War 2


Ribbon graphics not necessarily indicative of actual historical campaign ribbons. Ribbons are clickable to their respective campaigns / operations.

Advertisements





Disclaimer | Privacy Policy | Cookies


2022 Military Pay Scale Army Ranks Navy Ranks Air Force Ranks Alphabet Code DoD Dictionary American War Deaths French Military Victories Vietnam War Casualties

The "Military Factory" name and MilitaryFactory.com logo are registered ® U.S. trademarks protected by all applicable domestic and international intellectual property laws. All written content, illustrations, and photography are unique to this website (unless where indicated) and not for reuse/reproduction in any form. Material presented throughout this website is for historical and entertainment value only and should not to be construed as usable for hardware restoration, maintenance, or general operation. We do not sell any of the items showcased on this site. Please direct all other inquiries to militaryfactory AT gmail.com.

Part of a network of sites that includes GlobalFirepower, a data-driven property used in ranking the top military powers of the world, WDMMA.org, the World Directory of Modern Military Aircraft, and SR71blackbird.org, detailing the history of the world's most iconic spyplane.


Facebook Logo YouTube Logo

www.MilitaryFactory.com • All Rights Reserved • Content ©2003-