106mm M40



Overview


M40 Recoilless Rifle

M40 Recoilless Rifle seen without spotting rifle and the with the breech in open position.
Source: Forgotten Weapons - © Copyright lies with original owner

Origin
United States
Type
Recoilless rifle
Entered service
1955
Status
In service
Development
Early 1950's
Developer
United States - Watervliet Arsenal
Production
Mid 1950's - present
Producer
United States - Watervliet Arsenal
Austria - Lohner
India - OFB
Iran - DIO
Pakistan - PMT
South Korea - Kia
Spain - Santa Barbara
Number produced
Produced in large numbers
Designations
M40 Recoilless Rifle (USA)
10.6 cm rPAK M40A1 (Austria)
Canon sin retroceso 106mm (Spain)
Kanon, Rekylfri, 106mm (Norway)
Type 51 (Taiwan)

Description


Introduction

The M40 is an early Cold War era recoilless rifle of US origin. It was developed in the mid 1950's to replace the unsuccessful M27 developed several years earlier. Due to its excellent firepower, ample choice of ammunition types and good range the M40 was a very successful weapon. It was widely exported and although the use of recoilless rifles has reduced drastically the M40 remains in widespread use.

Design

The M40 has a conventional design for a recoilless rifle. The M40 has a long rifled barrel, features side swiveling breech block, is attached to a tripod with a single castor wheel and is fitted with a 12.7mm spotting rifle. The M40 actually is a 105mm weapon but is designated a 106mm weapon in order to not accidentally load 105mm ammunition for the earlier M27. The M40 fires single piece ammunitions, of which many types are available.

Firepower

A wide variety of ammunition types is available for the M40 and each has its own effective range and performance. HEAT rounds can be considered the standard type of ammunition and are effective up to 1.350 meters and penetrate over 400mm RHA. Explosive rounds can be used up to 2 or 3 km and APERS rounds that fire flechettes up to 300 meters. The sustained rate of fire is 1 round per minute, although a rate of fire of 5 rpm can be attained for short periods.

Mobility

The M40 is generally used on a light vehicle due to its weight and due to its firing signature. However, the M40 on its tripod can be manhandled over short distances. The vehicle most often used to carry the M40 is the M151 Mutt, but a Land Rover Defender, Toyota Land Cruiser, BJ-2020 and other 4x4 vehicles are common as well. In some nations the M40 is also carried on armored personnel carriers such as the M113 or Casspir. The M50 Ontos was a US tank destroyer with 6 guns and the Japanese Type 60 had two M40's as armament.

Users

The M40 was used by the United States military and most European nations. Most have been replaced by guided missiles, making the M40 very uncommon in Western nations. The M40 remains in widespread use in Asia, Africa, the Middle East and South America. With the introduction of anti-tank missiles the M40 is often relegated to a secondary role and nowadays is mostly used as a support weapon for infantry operations.

Variants


M40 Recoilless Rifle

Greek soldiers reloading a 106mm M40 Recoilless Rifle around 1997.
Source: BasilioC - © Public domain

Variants of the M40

The M40 is one of the most successful recoilless rifles ever produced. Among the large caliber recoilless rifles it is by far the most common model. Several types of M40 have been produced.

The M40, M40A1 and M40A2 are slightly improved production models and all use the original M79 heavy tripod with castor wheel. The M40A4 is a M40A2 that uses a lighter and more conventional M27 three leg tripod.

Most M40 that are produced under license are similar to the US production models. The Austrian M40's were fitted on a two wheel carriage, allowing the M40 to be towed by a vehicle and more easily manhandled into a firing position.

Details


Facts M40A2
General
Origin
United States
Type
Recoilless rifle
Crew
4 to 5
Dimensions
Weight
209.5 kg
Length
3.404 m
Tube length
2.692 mm
Width
800 mm tripod legs closed
1.524 mm tripod legs open
Height
1.118 mm
Ammunition
Ammunition types
105 x 607mmR
Rate of fire
1 rpm sustained
5 rpm maximum for short duration
Warhead
Diameter
105 mm
Warhead type
Wide range of ammunition available
Velocity
503 m/s for M344 HEAT
Range
1.3 km for HEAT
0.3 km for APERS
2 to 3 km for HE
7.7 km indirect fire range
Mount
Type
M79 tripod with castor wheel
Elevation
-17 to +65° between tripod legs
-17 to +27° over tripod legs
Traverse
360°
Fire control
Sights
Optical sight
Spotting rifle
12.7mm M8C

Media


Related articles


M50 Ontos

The M50 Ontos is an American tank destroyer armed with six 106mm M40A1C recoilless rifles.

Type 60

The Japanese Type 60 is a tank destroyer armed with two 106mm M40 on a raiseable mount.

107mm B-11

The B-11 is a contemporary Soviet recoilless rifle of a similar size and caliber.