The M114 155 mm howitzer was a towed howitzer used by the United States Army. It was first produced in 1942 as a medium artillery piece under the designation of 155 mm Howitzer M1. It saw service with the US Army during World War II, the Korean War, and the Vietnam War, before being replaced by the M198 howitzer. The gun was used by the armed forces of many nations, including Argentina, Austria, Brazil, Cambodia, Canada, Chile, Denmark, Ecuador, Greece, Iran, Iraq, Israel, Jordan, South Korea, Lebanon, Libya, Norway, the Philippines, Portugal, Saudi Arabia, Singapore, Taiwan, Thailand, Turkey, Venezuela, Vietnam, and Yugoslavia. One hundred sixteen surplus howitzers were sent to Bosnia in 1997. In some countries the M114 still remains in service.

Development

A new carriage was under development for much of the 1930s for the existing WW I-era M-1918 155 mm howitzer, which was a license-built French Canon de 155 C modèle 1917 Schneider until 1939 when it was realized that it didn't make a whole lot of sense to put a new carriage underneath an obsolete howitzer. So development began anew with a carriage designed to be used for either the 155 mm howitzer or the gun. This was completed by 15 May 1941 when the Howitzer M1 on the Carriage M- was standardized.
The howitzer itself differed from the older model by a lengthened barrel of 20 calibers and a new breech mechanism. Uniquely it was the sole 'slow-cone' interruped screw mechanism to enter service after 1920. This meant that two separate movements were necessary to open the breech, vice the single movement of the 'steep cone' mechanism that simultaneously rotated and withdrew the breech.
Post-war the M1 was redesignated as the M114.

Carriage variants

The carriage was also used by the 4.5 inch Gun M-1. It went through a number of minor changes over time. The original Warner electric brakes were replaced by Westinghouse air brakes on the M1A1. Both the M1 and M1A1 carriages used a mid-axle firing pedestal that was extended by a ratchet mechanism. The M1A2 replaced the ratchet with a screw-jack system and also modified the traveling lock. The M1A1E1 carriage was intended for use in jungle and muddy terrain and replaced the wheels of the M1A1 with a free-wheeling tracked suspension, but the project was terminated after V-J day without having reached production. The T-9 and T-10 carriages were projects using low-grade steel alloys that were canceled when no longer needed. The T-16 was a light-weight carriage using high-grade steel that was estimated to save some ; work began in July 1945 and continued after the war, although nothing seems to have come from it .

Self-propelled mounts

The howitzer was experimentally mounted on a lengthened chassis of the M5 light tank. The resulting vehicle received the designation 155 mm Howitzer Motor Carriage T64. A single prototype was built before the T64 project was abandoned in favor of T64E1, based on the M24 Chaffee light tank chassis. This was eventually adopted as 155mm Howitzer Motor Carriage M41 and saw action in the Korean War.

Ammunition

The gun fired separate loading, bagged charge ammunition, with seven different propelling charges, from 1 (the smallest) to 7 (the largest). Muzzle velocity, range and penetration in the tables below are for maximum charge in form of complete M4A1 propelling charge.

Projectiles
Type	Model	Weight of projectile, kg	Filler	Muzzle velocity, m/s	Range, m
HE	HE M102 Shell	43.13	TNT, 7.06 kg
HE	HE M107 Shell	43	TNT, 6.86 kg	564	14,955
Smoke	FS M105 Shell	45.14	Sulfur trioxide in Chlorosulfonic acid, 7.67 kg
Smoke	WP M105 Shell	44.55	White phosphorus (WP), 7.08 kg
Smoke	FS M110 Shell	45.45	Sulfur trioxide in Chlorosulfonic acid, 7.67 kg
Smoke	WP M110 Shell	44.63	White phosphorus (WP), 7.08 kg
Smoke, colored	BE M116 Shell	39.21	Smoke mixture, 7.8 kg
Smoke	HC BE M116 Shell	43.14	Zinc chloride (HC), 11.7 kg	564	14,955
Chemical	CNS M110 Shell	44.05	Chloroacetophenone (CN), 6.26 kg
Chemical	H M110 Shell	43.09	Mustard gas, 5.02 kg	564	14,972
Illumination	Illuminating M118 Shell	46.77	Illuminant candles, 4.02 kg
Drill	Dummy Mk I Projectile		-	-	-
Drill	Dummy M7 Projectile	43.09	-	-	-

 

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Propelling charges'''
Model	Weight, complete, kg	Components
M3	2.69	Base charge and four incremental charges (for charges 1 to 5)
M4	6.29	Base charge and two incremental charges (for charges 5 to 7)
M4A1	6.31	Base charge and four incremental charges (for charges 3 to 7)
Mk I Dummy	3.63	Base charge and six incremental charges
M2 Dummy	3.34	Base charge and six incremental charges

 

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Concrete penetration, mm
Ammunition Distance, m	0	914	2743	4572
HE M107 Shell (meet angle 0°)	884	792	610	488
Different methods of measurement were used in different countries / periods. Therefore, direct comparison is often impossible.

Notes

References

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• The M114 155 mm howitzer. FAS Military Analysis Network. .