Editing M110 howitzer

{{Short description|203 mm Self-propelled artillery}}
{{Use dmy dates|date=June 2017}}
{{Infobox weapon
|name=8" M110 self-propelled howitzer
|image=File:Dutch M110 203 mm 8 inch Heavy Self-propelled Howitzer.jpg
|image_size = 300
|caption=M110 203 mm self-propelled howitzer of the [[Royal Netherlands Army]]
|origin= United States
|manufacturer=[[General Motors]] (transmission)<ref>[https://babel.hathitrust.org/cgi/pt?id=uc1.c2790785;view=1up;seq=205 ''Defense Industry Bulletin''], April 1968, p. 47.</ref>
|wars=[[Vietnam War]] <br/> [[Yom Kippur War]] <br/> [[Iran–Iraq War]] <br/> [[1982 Lebanon War]] <br/> [[Kurdish–Turkish conflict (1978–present)]] <br/> [[Gulf War]] <br/> [[2025 India–Pakistan border skirmishes]]<ref>{{cite web |title=Reports of heavy fire at Leepa Valley between the Indian and Pakistani militaries, per local reports. Pakistan is sending hardware to the region, including the M110 self-propelled artillery system Leepa Valley |url=https://kashmir.liveuamap.com/en/2025/26-april-19-reports-of-heavy-fire-at-leepa-valley-between |website=Map of conflict in Jammu and Kashmir - India Pakistan - kashmir.liveuamap.com |access-date=27 April 2025 |language=en}}</ref>
|type=[[Self-propelled artillery]]
|crew=13 (driver, 2 gunners, 2 loaders, (8 support crew–other vehicle))
|length={{convert|10.8|m|ftin|abbr=on|disp=flip}}
|width={{convert|3.1|m|ftin|abbr=on|disp=flip}}
|height={{convert|3.1|m|ftin|abbr=on|disp=flip}}
|weight={{convert|31.2|ST|t LT|abbr=on}}
|armour= .51 in (13 mm)
|primary_armament=8 in (203 mm) M201A1 howitzer<br />
|secondary_armament= none
|engine=Detroit Diesel 8V71T, 8-cylinder, 2-stroke, turbocharged diesel
|engine_power=405 hp (302 kW)
|suspension=[[Torsion bar]]
|speed= {{convert|54.7|km/h|mph|abbr=on|sigfig=1|disp=flip}}
|pw_ratio=
<!-- Type selection -->
| is_ranged          =  yes
| is_bladed          = 
| is_explosive       = 
| is_artillery       = yes
| is_vehicle         = Yes
| is_missile         = 
| is_UK              = 
<!-- Ranged weapon specifications -->
|cartridge= 
|cartridge_weight=
|caliber={{convert|203|mm|abbr=on}}
|barrels=1
|action=
|elevation=
|traverse=
|rate=
|range={{convert|16.8-25|km|abbr=on}}<br />RAP {{convert|30|km|abbr=on}}
|max_range= 
|feed=
|velocity= 
|sights= 
<!-- Artillery specifications -->
|breech=
|recoil= 
|carriage=
}}

The '''8-inch (203&nbsp;mm) M110 self-propelled howitzer''' is an American self-propelled artillery system consisting of an [[M115 203 mm howitzer]] installed on a purpose-built chassis. Before its retirement from US service, it was the largest available [[Self-propelled artillery|self-propelled]] [[howitzer]] in the [[United States Army]]'s inventory; it continues in service with the armed forces of other countries, to which it was exported.<!--see Operators section--> Missions include general support, [[counter-battery fire]], and [[suppression of enemy air defense]] systems.

==Description==
According to the operator's manual, the M110's typical rate of fire was three rounds per two minutes when operated at maximum speed, and one round per two minutes with sustained fire. The M110 featured a hydraulically operated rammer to automatically chamber the {{convert|200|lb|abbr=on}}+ projectile. These rammers were prone to breakdown and generally slowed operation of the gun because the rammers required crews to completely lower the massive barrel before using it. Well trained and motivated crews could achieve two to four rounds per minute for short periods by using the manual rammer, essentially a heavy steel pole with a hard rubber pad on one end. Using the manual rammer was physically demanding, but crews were not required to lower the barrels as much as with the hydraulic rammer.

The M110's range varied from {{convert|16.8|km|mi|abbr=on|disp=flip}} to approximately {{convert|25|km|mi|abbr=on|disp=flip}} when firing standard projectiles, and up to {{convert|30|km|mi|abbr=on|disp=flip}} when firing rocket-assisted projectiles.<ref name=mtart>{{cite news |url=http://www.military-today.com/artillery/m110.htm |archive-url=https://web.archive.org/web/20081210044438/http://www.military-today.com/artillery/m110.htm |url-status=usurped |archive-date=10 December 2008 |title=The M110 at Military-today.com}}</ref>

==History==
The M110 howitzer first entered service with the U.S. Army in 1963 and was used in the [[Vietnam War]] by the [[United States Army]]. Later versions were used in the [[Gulf War]] - [[Gulf War#Operation Desert Shield|Operation Desert Shield]] and [[Operation Desert Storm]] by Tango Battery [[5th Battalion 11th Marines]], and the [[British Army]]'s [[32nd Regiment Royal Artillery]].<ref>[https://www.youtube.com/watch?v=dJfcVG8mu_s 32 Regiment RA in action - Gulf War 1991]</ref>

In 1977 the upgraded M110A1 entered service, featuring a longer M201 series barrel which gave it an increased range. The final version, the M110A2, added a double [[muzzle brake]]. The M110A2s were made from refitted M110s or [[M107 self-propelled gun|M107 175&nbsp;mm self-propelled guns]].<ref>(Hunnicutt)</ref> The 2nd Battalion 18th Field Artillery (U.S. Army), which inactivated in 1994 at [[Fort Sill]], Oklahoma, and the 5th Battalion 18th Field Artillery served in Desert Storm with the M110A2, as did the 142nd Field Artillery Brigade ([[Arkansas Army National Guard]]) and 1st Battalion 181st Field Artillery ([[Tennessee Army National Guard]]). Most of the U.S. Army and Marine Corps relied on [[M109 howitzer|M109 series 155-millimeter howitzer]] systems during this conflict, sending remaining M110s to reserve or National Guard units. These units then took possession of M109s as they returned from combat operations. M110s were still in service with the 3rd Battalion 92nd Field Artillery (US Army Reserve) and running fire missions at [[Camp Atterbury]] as late as the summer of 1994.<ref name="youtube-gulf-war-1991">[https://www.youtube.com/watch?v=dJfcVG8mu_s UK M110 Artillery in action Gulf War 1991]</ref>

The howitzer has been retired from U.S. Army service, replaced by the [[M270 multiple launch rocket system]].

[[File:Dutch M110 203 mm Howitzer in Firing Position 1972.jpg|thumb|left|Dutch artillerymen with their M110 in firing position, 1972]]

At the end of the Cold War under U.S. Division Plan 86, all armored and [[mechanized infantry]] divisions included a battalion of heavy artillery that included two batteries of M110A2 SP howitzers with six guns each for a total of 12 guns, plus one battery of nine [[M270 multiple launch rocket system|M270s]].{{citation needed|date=August 2017}}

Israel used M110s along with M107s during the [[Yom Kippur War]] against Egyptian and Syrian forces. Later, in 1982, Israel used M110 systems against the [[Palestine Liberation Organization]] and their Lebanese allies with deadly effect during the [[Siege of Beirut]] as part of [[Operation Peace for Galilee]].{{citation needed|date=February 2022}}

Iran used its M110s during its offensives against Iraq in the [[Iran–Iraq War]].{{citation needed|date=February 2022}}

The [[Turkish Armed Forces]] have used M110A2 systems against the [[Kurdistan Workers' Party]] since the 1990s, as well as in the [[Turkish occupation of northern Syria|Turkish military intervention in Syria]], mainly against the [[People's Protection Units]].{{citation needed|date=February 2022}}

==Projectiles==
[[Image:Mk33.jpg|right|thumb|upright=1.2|A 203 millimetre W33 nuclear artillery shell on display]]
* M14 dummy
* M106 HE
* [[M650]] HE rocket assist projectile (RAP)
* [[M509]] ICM
* [[M404]] ICM anti-personnel (airburst)
* [[M426 8-inch shell|M426]] agent GB [[Sarin]]
* [[W33 (nuclear warhead)|M422A1 Artillery Fired Atomic Projectile]]<ref name=NRDC>{{cite report |author1=Thomas B Cochran |author2=William M Arkin |author3=Milton M Hoenig |date=1984 |title=Nuclear Weapons Databook, Volume I: US Nuclear Forces and Capabilities |url=https://fas.org/nuke/cochran/nuc_84000001b_01.pdf |publisher=Natural Resources Defense Council |page=47 |access-date=2021-06-22 |archive-date=2021-09-01 |archive-url=https://web.archive.org/web/20210901023751/https://nuke.fas.org/cochran/nuc_84000001b_01.pdf |url-status=live }}</ref>
* M424 High Altitude Spotting Round for the M422 projectile
* [[W79 Artillery-Fired Atomic Projectile|XM753 Atomic RA (rocket assisted)]]<ref name=Arty>{{cite report |author=Henry E Hudgins |date=January 1977 |title=Aerodynamics, Dimensions, Inertial Properties and Performance of Artillery Projectiles |url=https://apps.dtic.mil/dtic/tr/fulltext/u2/b022223.pdf |publisher=Picatinny Arsenal |page=4 |access-date=2021-12-24 |archive-date=2021-12-19 |archive-url=https://web.archive.org/web/20211219101132/https://apps.dtic.mil/dtic/tr/fulltext/u2/b022223.pdf |url-status=live }}</ref>

==Operators==
[[File:M110 operators.png|thumb|upright=1.6|Map with M110 operators in blue and former operators in red]]
[[Image:M110 Column.JPEG|thumb|right|U.S. Army M110A2 howitzers in a staging area prior to transport, [[Port of Antwerp]], 1984]]

===Current operators===
*{{BHR}}: [[Royal Bahraini Army]] 13 as M110A2 from Netherlands delivered in 1994,<ref name="sipri">{{cite web|url=http://armstrade.sipri.org/armstrade/page/trade_register.php|author=Stockholm International Peace Research Institute|title=Transfers and licensed production of major conventional weapons|access-date=2011-12-10}}</ref> 25 as M110A2 from US delivered in 1996.<ref>{{cite web|url=http://www.dsca.mil/programs/eda/search.asp |author=Defense Security Cooperation Agency |title=Excess Defense Articles |access-date=2011-12-10 |url-status=dead |archive-url=https://web.archive.org/web/20120114174201/http://www.dsca.mil/programs/eda/search.asp |archive-date=2012-01-14 }}</ref>
*{{CYP}}: [[Cypriot National Guard]] 8 as M110A2<ref>{{Cite web |title=Εξοπλισμός Εθνικής Φρουράς (Κύπρος) |url=https://www.ellinikos-stratos.com/stratos/cyprus |access-date=2023-07-03 |website=www.ellinikos-stratos.com}}</ref>
*{{GRC}}: [[Hellenic Army]] 145 as M110A2.
*{{EGY}}: [[Egyptian Army]] Received 144 as M110A2 as aid in 1996.<ref>{{cite web | work= Federation of American Scientists |url= https://fas.org/asmp/library/asm/asm33table2.html |title= Deals in the Works | access-date= 29 March 2011}}</ref>
*{{IRN}}: [[Iran Army]] 30 M110.
*{{JOR}}: [[Jordanian Armed Forces]] 120 as M110A2.
*{{MAR}}: [[Moroccan Army]] 60 as M110A2.
*{{PAK}}: [[Pakistan Army]] 140 in service as of 2021.
*{{TWN}}: [[Republic of China Army]] 70 M110A2 as of 2023<ref name="IISS2023">{{cite book |last1=International Institute for Strategic Studies |title=The Military Balance 2023 |date=February 2023 |publisher=Routledge, Chapman & Hall, Incorporated |isbn=978-1-032-50895-5 |url=https://books.google.com/books?id=U86kzwEACAAJ |access-date=19 August 2023 |language=en |author1-link=International Institute for Strategic Studies }}</ref>{{rp|291}}<ref name="Janes">{{cite book |last1=Foss |first1=Christopher F. |title=Jane's Armour and Artillery 2005-2006 |date=2005 |publisher=Jane's Information Group |isbn=978-0-7106-2686-8 |url=https://books.google.com/books?id=e8_HAAAACAAJ |access-date=19 August 2023 |language=en}}</ref>{{rp|1021}}
*{{TUR}}: [[Turkish Army]] currently phasing out 219 as M110A2 in favor of [[T-155 Fırtına]]

===Former operators===
*{{BEL}}: [[Belgian Army]] 11 M110A2 between 1972 and 1993 used by the 20th Artillery Regiment ([[Belgian Forces in Germany]]).
*{{GER}}: [[German Army]] M110A2 until 1993.
*{{ISR}}: [[GOC Army Headquarters|Israeli Army]] 36 as M110, retired in 1990s.
*{{ITA}}: [[Italian Army]] used M110A2s, phased out by 1998.
*{{JPN}}: [[Japan Ground Self-Defense Force]] 91 as M110A2. As of 2023, approximately 10 M110A2s were in active, owned by 104th Artillery Battalion of 4th Artillery Group (Mechanized) in [[Hokkaido]].<ref>{{cite web |last1= Yusuke |first1= Tsuge | work= Vehicle news |url= https://trafficnews.jp/post/125248/2 |title= 陸自最大サイズの巨砲「203mm自走りゅう弾砲」まもなく退役 進む"火砲リストラ" 最後の部隊は | access-date= 28 September 2023}}</ref> They retired in March 2024 and the battalion was disbanded.<ref>{{cite web | work= Motor-Fan CAR |url= https://motor-fan.jp/mf/article/214490/ |title= 昭和の名戦車「74式戦車」ついに完全引退！ 2024年3月をもって本州から戦車部隊が消滅【自衛隊新戦力図鑑】 | access-date= 17 April 2024}}</ref>
*{{KOR}}: [[Republic of Korea Army]] Operated M110 since 1961. Retired in the late 2000s after being replaced by [[K9 Thunder]].<ref>{{Cite book |last=Bak |first=Dongchan |url=http://medcmd.mil.kr/user/imhc/upload/pblictn/PBLICTNEBOOK_202105270240172800.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://medcmd.mil.kr/user/imhc/upload/pblictn/PBLICTNEBOOK_202105270240172800.pdf |archive-date=2022-10-09 |url-status=live |title=Korean War : Weapons of the United Nations |publisher=Ministry of Defense Institute for Military History |date=March 2021 |isbn=979-11-5598-079-8 |location=Republic of Korea |pages=108–110 |language=Korean}}</ref>
*{{flagcountry|South Vietnam}}: [[Army of the Republic of Vietnam]].
*{{NLD}}: [[Royal Netherlands Army]] M110A1 and M110A2, replaced by the M109 in the 1990s
*{{SPN}}: [[Spanish Army]] as 64 M110A2, deployed in divisional fire support regiments until 2009.
*{{UK}}: [[British Army]] as M110A2 firing high explosive and nuclear shells only. (The [[FV433 Abbot SPG]], the [[M109 howitzer|M109A2]], and the M110A1 were replaced by the [[AS-90]] in the early-mid-1990s.) Used in [[Operation Granby]]/[[Gulf War]].<ref name="youtube-gulf-war-1991"/>
*{{USA}}: Used by [[United States Army]] and [[United States Marine Corps]], M110A2s retired in 1994.

==See also==
* [[List of U.S. military vehicles by model number]]
* [[2S7 Pion]] – Soviet L/55.3 203&nbsp;mm self-propelled cannon
* [[2S4 Tyulpan]] – Soviet 240&nbsp;mm self-propelled mortar
* [[List of crew-served weapons of the US Armed Forces]]
* [[M55 self-propelled howitzer|M55]] – 203&nbsp;mm self-propelled gun, predecessor to the M110
* [[M107 self-propelled gun|M107]] – a 175&nbsp;mm self-propelled gun on the same chassis
* [[Merkava#Merkava Howitzer Sholef|Sholef]] – Israeli 155&nbsp;mm self-propelled howitzer
* [[T92 Howitzer Motor Carriage]] – a [[240 mm howitzer M1]] fitted on a [[M26 Pershing]] chassis

==References==
{{Reflist}}
* TM 9-2350-304-10 dated October  1979

==External links==
{{Commons|M110 203 mm self-propelled howitzer}}
*[https://fas.org/man/dod-101/sys/land/m110a2.htm fas.org.]
*[http://www.primeportal.net/artillery/m110_home.htm M110 Walk Arounds on Prime Portal]
*https://www.militaryfactory.com/armor/detail.asp?armor_id=59

{{Authority control}}

[[Category:Cold War artillery of the United States]]
[[Category:Self-propelled howitzers of the United States]]
[[Category:Tracked self-propelled howitzers]]
[[Category:203 mm artillery]]
[[Category:Military vehicles introduced in the 1960s]]