View source for M101 howitzer

{{Short description|US-made towed howitzer}}
{{Use dmy dates|date=February 2023}}
{{Use American English|date=February 2023}}
{{Infobox weapon
|name=M101 105mm light howitzer, towed
|image=M101-105mm-howitzer-camp-pendleton-20050326.jpg
|image_size=300
|caption=United States Marines fire a M101A1 during a ceremony in 2005
|origin=United States
|type=[[Howitzer]]
<!-- Type selection -->
|is_ranged=yes
|is_bladed=
|is_explosive=
|is_artillery=yes
|is_vehicle=
|is_UK=
<!-- Service history -->
|service= 1941–present
|wars= {{Collapsible list
| bullets = yes
| title = List of Conflicts
| [[World War II]]
| [[Chinese Civil War]]
| [[Korean War]]
| [[First Indochina War]]
| [[Vietnam War]]
| [[Cambodian Civil War]]
| [[Laotian Civil War]]
| [[Football War]]
| [[Insurgency in the Philippines]]
| [[Rhodesian Bush War]]
| [[Iran–Iraq War]]
| [[Lebanese Civil War]]
| [[Nicaraguan Revolution]]
| [[Salvadoran Civil War]]
| [[Yugoslav Wars]]
| [[Battle of Marawi]]
| [[Russo-Ukrainian War]]
| [[Yemeni civil war (2014–present)|Yemeni Civil War]]
}}
<!-- Production history -->
|designer=
|design_date=
|manufacturer=[[Rock Island Arsenal]]<br />[[Hyundai Wia|Kia Machine Tool]]
|production_date=1941–1953
|number=10,200
|variants=
<!-- General specifications -->
|weight={{convert|2260|kg|lb|abbr=on|order=flip}}
|length={{convert|5.94|m|ftin|abbr=on|order=flip}}
|part_length={{convert|2.31|m|ftin|abbr=on|order=flip}} L/22
|width={{convert|2.21|m|ftin|abbr=on|order=flip}}
|height={{convert|1.73|m|ftin|abbr=on|order=flip}}
|crew=
<!-- Ranged weapon specifications -->
|cartridge=105×372 mm R
|caliber={{convert|105|mm|in|abbr=on}}
|action=
|rate=
|velocity={{convert|472|m/s|ft/s|abbr=on|order=flip}}
|range=
|max_range={{convert|11,270|m|mi|abbr=on|order=flip}}
|feed=
|sights=
<!-- Artillery specifications -->
|breech=[[Rifled breech loader#The sliding block|Horizontal-block]]
|recoil=[[Hydraulic recoil mechanism|Hydro-pneumatic]], constant, {{convert|42|in|cm|abbr=on}}
|carriage=[[split trail]]
|elevation= −5° (−89 mils) to<br />
65° (1,156 mils)
|traverse= ±23° (±409 mils)
}}

The '''M101A1''' (previously designated '''Howitzer M2A2 on Carriage M2A2''') howitzer is an artillery piece developed and used by the United States. It was the standard U.S. light field howitzer in [[World War II]] and saw action in both the [[European Theatre of World War II|European]] and [[Pacific Ocean theater of World War II|Pacific theaters]] and during the [[Korean War]]. Entering production in 1941, it quickly gained a reputation for accuracy and a powerful punch. The M101A1 fires [[105 mm]] [[Explosive material#High explosives|high explosive]] (HE) [[Shell (projectile)#Separate loading cased charge|semi-fixed]] ammunition and has a range of {{convert|11,270|m|yards|order=flip}} or 7 miles, making it suitable for supporting [[infantry]].

==History==

===Development and designation===

After World War I, the U.S. Army Ordnance Department studied various captured German 105&nbsp;mm-caliber howitzers and developed the 105&nbsp;mm Howitzer M1920 by using the Carriage M1920. A box trail carriage design (the M1925E carriage) and two other split trail designs (the T1 and T2) were also developed, but the original split trail design was found superior after testing. After being selected, the piece was standardized in December 1927, as the 105&nbsp;mm howitzer M1 on carriage M1. The Army had an intention to replace all [[Canon de 75 modèle 1897|75 mm gun-howitzers]] in its divisional and non-divisional field artillery regiments with 105&nbsp;mm pieces, but a lack of appropriations stalled the idea and eventually forced it to be completely abandoned by 1929; a limited plan developed in 1925 envisioned re-equipping three regiments, but by 1933, only 14 M1 howitzers had been manufactured.

A modified version of the M1 was trialed in 1932 which used semi-fixed ammunition instead of separate-loading ammunition. Since this development required a different breech block, the new piece was designated the 105&nbsp;mm howitzer M2 on carriage M1. 48 pieces were manufactured in 1939. The original M1 carriage had been designed for towing using horses rather than trucks, and a new carriage, the T5 (M2), was developed in 1939 and standardized in February 1940. The breech ring of the howitzer M2 was modified in March 1940 before large-scale production began, creating the 105&nbsp;mm howitzer M2A1 on carriage M2.<ref>{{cite book |last=Zaloga|first=Steven|date=2011|title=U.S. Field Artillery of World War II|publisher=Osprey Publishing |series=New Vanguard 131|pages=10–11}}</ref>

In 1939, the new howitzer cost $25,000, which was three times more than a [[75 mm field gun M1897 on M2 carriage]], and its adoption required procurement of a colossal amount of new ammunition (War Department estimate of $26 million).<ref>{{cite web | url=https://books.google.com/books?id=AIY0AAAAIAAJ&pg=PA470 | title=Third Deficiency Appropriation Bill for 1939: Hearings Before the Subcommittee of the Committee on Appropriations, House of Representatives, Seventy-sixth Congress, First Session on the Third Deficiency Appropriation Bill for 1939 | year=1939 }}</ref>

The gun was designed to be very durable and was therefore heavy for its caliber,<ref>Bishop, Chris. The encyclopedia of weapons of world War II. Sterling Publishing Company, Inc., 2002, p.139</ref> but studies after 1943 found that after prolonged firing, the muzzle end of the barrel was prone to cracking. To relieve stress in the barrel, new production M2A1 tubes were counterbored two inches from the muzzle starting in the late 1940s. By the end of World War II, 8,536 105&nbsp;mm towed howitzers had been built and post-war production continued at Rock Island Arsenal until 1953, by which time 10,202 had been built.

In 1953, the new howitzer M2A2 was standardized to further increase the life of the howitzer at the cost of some muzzle velocity. The M2A2's barrel had a higher strength breech ring, deeper rifling grooves, and shallower rifling taper than the M2A1's barrel, resulting in a 50 percent more effective full charge barrel life than the M2A1.<ref>{{Cite book |url=https://apps.dtic.mil/sti/pdfs/ADA134349.pdf |title=Field Artillery Cannon Weapons Systems and Ammunition Handbook. |date=1 January 1983 |publisher=U.S. Army Field Artillery School |location=Fort Sill, Oklahoma |pages=49}}</ref>

A further developed howitzer M2A2E2, featuring a muzzle brake and maximal range increased along with the propelling charge,<ref>{{Cite book |last=Center (U.S.) |first=Defense Documentation |url=https://books.google.com/books?id=gElHhhYud-IC&pg=RA2-PP7 |title=Technical Abstract Bulletin |date=February 1961 |publisher=Armed Services Technical Information Agency. |language=en}}</ref> on carriage M2A2E2, featuring an increased maximal angle of fire,<ref>{{Cite book |url=https://books.google.com/books?id=yCZnGgoFZfcC&pg=RA1-PA54 |title=Army Information Digest |date=1960 |publisher=U.S. Department of the Army |language=en}}</ref> were designed and tested in 1958, but with the coming [[M102 howitzer|XM102 howitzer]] both were canceled in 1961.

In November 1960, U.S. military artillery designation system began to change, where howitzer M2A1 or M2A2 on carriage M2A1 were renamed the M101 and howitzer M2A1 or M2A2 on carriage M2A2 were renamed the M101A1. This howitzer continued to see service through the [[Vietnam War]]. Though the successor M102 howitzer was adopted in 1964, both M101 and M102 shared similar roles in battle and the M101A1 was never fully replaced in front-line service until the adoption of the [[M119 howitzer]]. Today, the M101A1 has been retired by the U.S. military, though it continues to see service with many other countries.

===Australia===
The M2A2 howitzer was retired from regular service with the [[Australian Army]] in 1988, when it was replaced by the 105&nbsp;mm [[L118 Light Gun|L118 and L119]],<ref>{{cite thesis |last=Swinsburg |first=Major Philip R. |date=2 June 2000 |title=The Australian Indirect Firepower Capability: Bridging the Paradigm from Industrial Age to Information Age Firepower |url=https://cgsc.contentdm.oclc.org/digital/api/collection/p4013coll2/id/537/download |degree=MSc |chapter=Chapter 3: Status of Present Capability |page=32 |publisher=[[United States Army Command and General Staff College]] |location=Fort Leavenworth, Kansas |access-date=9 July 2024}}</ref> which in turn were replaced by the [[M777 howitzer|M777A2]] in 2014.<ref>{{cite press release |author=<!--Not stated--> |date=6 September 2016 |title=Hamel retired from 53 Bty |url=https://www.army.gov.au/media-room/media-releases/hamel-retired-from-53-bty |url-status=dead |publisher=Australian Army |archive-url=https://web.archive.org/web/20170305043405/https://www.army.gov.au/media-room/media-releases/hamel-retired-from-53-bty |archive-date=5 March 2017 |access-date=9 July 2024}}</ref> The M2A2 remained in service with the [[Australian Army Reserve]] until its replacement by {{convert|81|mm|in|adj=on}} mortars in the late 2000s.<ref>{{cite web |last=Toohill |first=MAJ Ian |title=Mortars for Reserve Gunners |url=http://www.defencereserves.com/cms_resources/TheBayonet_AUG09_v3.pdf |publisher=2nd Division, Army Reserves Public Affairs |work=The Bayonet |access-date=6 January 2012 |page=10 |date=August 2009 |url-status=dead |archive-url=https://web.archive.org/web/20120227102559/http://www.defencereserves.com/cms_resources/TheBayonet_AUG09_v3.pdf |archive-date=27 February 2012}}</ref> [[Australia's Federation Guard]] retains six pieces for ceremonial use.<ref>{{cite news |author=<!--not stated--> |date=11 April 2021 |title=Australia's Parliament House, British armed forces mark Prince Philip's death with 41-gun salute |url=https://www.abc.net.au/news/2021-04-10/australian-41-gun-salute-to-mark-passing-prince-philip/100061186 |work=[[ABC News (Australia)|ABC News]] |location=Sydney, Australia |access-date=9 July 2024}}</ref>

===Canada===
The [[Canadian Forces]] procured at least 60 US made M2A1 howitzers, beginning in 1952, and also had Sorel Industries of Canada produce 232 of a slightly modified M2A2 version, starting in 1955. The Canadian produced guns were later designated C1, while the US produced guns were designated C2. These continued in service until the early 2000s. In the late 1990s, ninety-six C1 guns were selected and sent to RDM in the Netherlands to extend their service life. These guns were re-designated as the C3. The changes include a longer 33-calibre barrel, a [[muzzle brake]], reinforced trails and the removal of shield flaps. It remains the standard light howitzer of Canadian Forces [[Canadian Forces Primary Reserve|Reserve]] units. The C3 is used by 1RCHA in [[Glacier National Park (Canada)|Glacier National Park]] in [[British Columbia]] as a means of [[avalanche]] [[avalanche control|control]]. The C3 is used to train Regular Force Artillery in Shilo MB. The modified 105mm C3 howitzer has a range of 18km.<ref>{{cite web |url=https://www.canada.ca/en/army/services/equipment/weapons/c3-105mm-howitzer.html |title=C3 105-mm Howitzer |author=<!--Not stated--> |date=16 February 2021 |website=Government of Canada |access-date=23 August 2024}}</ref>

===Croatia===
A number of M2/M101 howitzers were used by the [[Socialist Federal Republic of Yugoslavia]] and approximately 50 were inherited by [[Croatia]], of which four are still in use for training with the [[Croatian Army]].{{citation needed|date=March 2019}}

===France===
[[File:French artillerymen of the 65th Artillery Regiment being instructed on 105mm M2 Howitzer, 2 December 1943.jpg|thumb|French artillerymen of the 65th Artillery Regiment being instructed on 105mm M2 Howitzer in [[French protectorate in Morocco|Morocco]], December 1943.]]
The French Army used the M2 howitzer, designated ''HM2'', during World War II,<ref>{{Cite book |last=Gaujac |first=Paul |title=L'armée de la victoire |date=1984 |publisher=Charles-Lavauzelle |isbn=2-7025-0055-2 |location=Paris |page=4 |language=fr |oclc=12664929}}</ref> in the [[Algerian War]]<ref>{{cite journal|last=Jung|first=Norbert|date=2009|title=L'artillerie dans la lutte contre-insurrectionnelle en Algérie (1954–1962)|journal=Stratégique|issue=93-94-95-96|  volume=1|pages=409–424|doi= 10.3917/strat.093.0409|url= https://www.cairn.info/revue-strategique-2009-1-page-409.htm|language=fr|access-date=2019-03-14|archive-url=https://web.archive.org/web/20151209131413/http://www.cairn.info/revue-strategique-2009-1-page-409.htm|archive-date=2015-12-09|url-status=live|url-access=subscription}}</ref> and during the [[Opération Tacaud]] in [[Chad]].<ref>{{cite web|title=Quand tire l'artillerie|trans-title=When artillery fires|url=http://secretdefense.blogs.liberation.fr/2008/07/22/quand-tire-lart/|date=22 July 2008|author-link=Jean-Dominique Merchet|first=Jean-Dominique|last=Merchet|language=fr|website=secretdefense.blogs.liberation.fr|access-date=14 March 2019|archive-url=https://web.archive.org/web/20190329013741/http://secretdefense.blogs.liberation.fr/2008/07/22/quand-tire-lart/|archive-date=29 March 2019|url-status=live}}</ref> France later supplied a battery of HM2 to the [[Rwandan Armed Forces]] during the [[Rwandan Civil War]] that led into the [[Rwandan genocide]].<ref name="Rwanda" />

=== Germany ===
The [[German Army]] adopted the M101 howitzer in a modified form in March 1956, designated Feldhaubitze 105&nbsp;mm M1A2 (Bw).<ref>{{Cite book |title=Das Heer 1950 bis 1970: Konzeption, Organisation, Aufstellung |date=2006 |publisher=R. Oldenbourg |isbn=978-3-486-57974-1 |editor-last=Hammerich |editor-first=Helmut R. |series=Sicherheitspolitik und Streitkräfte der Bundesrepublik Deutschland |location=München |pages=750}}</ref> Using components made by [[Rheinmetall]], the new howitzers had a longer, un-counterbored 27-caliber barrel, a large single-baffle muzzle brake, and a larger gun shield.

===Philippines===
M2A1 howitzers were used by the [[Philippine Expeditionary Forces to Korea|PEFTOK]].{{cn|date=October 2024}} By the 1980s these wartime artillery pieces were replaced by M101s, and were used against the [[New People's Army|NPA]] and the [[MNLF]], and the [[Moro Islamic Liberation Front|MILF]].{{cn|date=October 2024}} Several M101 howitzers are still in use with the [[Armed Forces of the Philippines]] and are normally used to battle rebels in Luzon, Visayas, and Mindanao.{{cn|date=October 2024}} They were also used in direct fire against Islamic militants during the [[Battle of Marawi]].{{cn|date=October 2024}}

===South Korea===
{{Undue weight section|date=December 2021}}
Starting on 6 July 1950, South Korea received a total of 1,127 M2A1s until the end of the [[Korean War]] to supplement and replace the [[M116 howitzer|M1 75 mm howitzer]] and the [[M3 howitzer|M3 105 mm howitzer]].<ref name="Korean War : Weapons of the United Nations">{{Cite book |last=Bak |first=Dongchan |url=http://medcmd.mil.kr/user/imhc/upload/pblictn/PBLICTNEBOOK_202105270240172800.pdf |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=102–104 |language=Korean |access-date=2022-07-07 |archive-date=2022-09-20 |archive-url=https://web.archive.org/web/20220920170621/http://medcmd.mil.kr/user/imhc/upload/pblictn/PBLICTNEBOOK_202105270240172800.pdf |url-status=dead }}</ref>

In the early 1970s, the [[Republic of Korea Armed Forces|ROK Armed Forces]] needed to replace these old howitzers due to the maintenance burden. To match North Korea's artillery capability, South Korea invested in the domestic arms industry to equip its large military cost efficiently. After completion of ''Project Thunder I'', supported by the [[United States Department of Defense|U.S. Department of Defense]], for infantry weapons, in April 1972, the South Korean president [[Park Chung Hee]] ordered ''Project Thunder II'' for artillery weapons. The U.S. refused to cooperate due to the then [[1972 visit by Richard Nixon to China|diplomatic overtures]] to the [[People's Republic of China]]. The [[Embassy of the United States, Seoul|U.S. Embassy in South Korea]] ordered its technical team to withdraw, believing that South Korea lacked the tooling and knowledge to develop the weapons by itself. The [[Agency for Defense Development]] however, [[reverse engineered]] the M2A1 (M101A1), and prototype production began in March 1973.<ref name="KH178 Interview">{{Citation|title=[첨단국가의 초석, 방위산업] 자주국방의 포문을 열다 - KH-178 개발사| date=16 September 2015 |url=https://www.youtube.com/watch?v=aMebOqWzDgQ|language=en|access-date=2021-12-18}}</ref><ref name="KH178 Interview 2">{{Cite web|title=유용원의 군사세계 국산 105mm 견인야포 KH-178|url=https://bemil.chosun.com/nbrd/bbs/view.html?b_bbs_id=10044&num=38605|access-date=2021-12-19|website=유용원의 군사세계|language=ko}}</ref>

On 25 June 1973, three prototypes were demonstrated publicly. After the test, the U.S. ambassador [[Philip Habib]] arranged the meeting of South Korean chief secretary O Won-cheol and colonel Montgomery from the Joint U.S. Military Affairs Group-Korea. The colonel provided technical review of the howitzer, and recommended purchasing of the U.S. equipment for logistics issues because the howitzer was not compatible with the U.S. standard. South Korea refused and pursued domestic design, but the two nations eventually signed an agreement for technology transfer in September 1973. It was the first weapons research cooperation between the two nations, and the South Korean defense industry began to form with guidance from the U.S.<ref name="KH178 Interview" /><ref name="KH178 Interview 2" />

In February 1974, hostilities grew after North Korea sunk a South Korean fishing boat and kidnapped fishermen near [[Baengnyeongdo|Baengnyeong Island]]. As a response, 10 howitzers crafted prior to the research cooperation were sent to the island, but pulled out after having severe malfunctions during operations. In November 1975, the reinforced variant experienced barrel breakdown; the failure led to the invitation of American engineers in January 1976 for an overview. After 1.5 months of inspection, the engineers suggested the [[Eighth United States Army]] replace South Korean copy with the original M101A1 design. The U.S. then provided its technical data package to South Korea, which quickly readied mass production of the howitzer before the year ended. Production began in 1977 as KM101A1 by Kia Machine Tool (now [[Hyundai Wia]]) in [[Changwon]].<ref name="KH179">{{Citation|title=[첨단국가의 초석, 방위산업] 자주국방의 포문을 열다 - KH-179 개발사| date=16 September 2015 |url=https://www.youtube.com/watch?v=HoQheFq4Y5I|language=en|access-date=2021-12-22}}</ref><ref name="KH178">{{Cite web|date=2011-08-31|title=[한국의 무기 이야기](15) 천자총통에서 K9 자주포까지|url=https://segye.com/view/20110830004358|access-date=2021-12-21|website=세계일보|language=ko}}</ref>

In 1978, South Korea restarted domestic howitzer program based on M101A1. The howitzer applied 38 calibers barrel for extending the maximum range to 18&nbsp;km using RAP ammunition. Only 18 howitzers saw service with South Korean military in favor of mass-producing [[KH179 howitzer|KH179 155 mm towed howitzer]].<ref name="KH178" />

As of 2021, South Korea is the largest operator of the M101 howitzer with about 2,000 pieces in active service. It is planned to convert 1/3 of its inventory to K105A1 self-propelled howitzer.<ref>{{Cite web|last=국방일보|title=견인포에서 차륜형 자주포로 쉬워진 조작...기동·생존성 높아졌다|url=https://kookbang.dema.mil.kr/newsWeb/20210903/2/BBSMSTR_000000010263/view.do|access-date=2021-12-21|website=국방일보 |language=ko}}</ref>

===Vietnam===
[[France]] and the [[State of Vietnam]] used M2A1 howitzers during the [[First Indochina War]], as did the [[Viet Minh]] guerilla forces they fought against, who were supplied with at least 24 by the [[People's Republic of China]], along with other captured American artillery pieces and mortars formerly operated by both Nationalist Chinese forces (the [[Kuomintang]] military) and US troops [[Korean War|fighting in Korea]].{{citation needed|date=March 2019}} Today upgraded M2A1 howitzers (some of which have been mounted on trucks and employed as self-propelled artillery) are still being used by the [[People's Army of Vietnam]] (the PAVN).{{sfn|Military Balance 2016|p=297}}

===Other uses===
In addition, the M101 has found a second use in the U.S. as an [[Avalanche control|avalanche control gun]], supervised by the [[US Forest Service]] and the US Army [[TACOM]]'s cooperative effort in the Avalanche Artillery Users of North America Committee (AAUNAC).  The M101 is used by a number of ski areas and state departments of transportation for long-range control work. Under the designation of M2A2, the 2nd Battalion, [[2nd Field Artillery Regiment (United States)|2nd Field Artillery Regiment]], [[428th Field Artillery Brigade]] performs salutes with 7 guns with World War II Medal of Honor recipient names on their barrels.<ref>{{Cite web|url=https://sill-www.army.mil/428thfa/2-2/cmd.html|title=428th Field Artillery Brigade {{!}} Fort Sill {{!}} Oklahoma|website=sill-www.army.mil|access-date=2018-07-05|archive-url=https://web.archive.org/web/20180705033250/http://sill-www.army.mil/428thfa/2-2/cmd.html|archive-date=2018-07-05|url-status=live}}</ref>

==Variants==
Gun variants:
* M1920 – prototype.<ref name="HOGG-42">Hogg – ''Allied Artillery of World War Two'', p 42–49.</ref>
* M1925E – prototype.<ref name="HOGG-42" />
* T2 – prototype, standardized as M1.<ref name="HOGG-42" />
* M2 (1934) – minor changes to the chamber to allow the use of fixed ammunition.<ref name="HOGG-42" />
* M2A1 (1940) – modified breech ring.<ref name="TM-9-2005">''Technical Manual TM 9-2005 volume 3, Infantry and Cavalry Accompanying Weapons''.</ref>
* M2A2 (1953) – deeper rifling and shorter rifling taper.
* M2A2E2 (1958) – prototype with muzzle brake.
* [[M3 howitzer|M3]] – lightweight howitzer, with barrel shortened by {{convert|27|in|cm}} with carriage of the [[M116 howitzer|M1 pack howitzer]].
* T8 – prototype vehicle-mounted variant with modified breech and with cylindrical recoil surface, standardized as 105&nbsp;mm M4 howitzer in September, 1943.{{sfn|Hunnicutt|1994|p=210}}
* FH M1A2 – Rheinmetall-modified M101 in German service.
* M101 – post-1961 designation of M2A1 or M2A2 on carriage M2A1.
* M101A1 – post-1961 designation of M2A1 or M2A2 on carriage M2A2.
* M2A1 – modernized L33 variant by [[Yugoimport SDPR]] with max range of {{convert|15|km|abbr=on}}/{{convert|18.1|km|abbr=on}} (boat tail shell/base bleed shell)<ref>{{cite web |url=http://www.yugoimport.com/sites/default/files/knjizica_za_cargo_dvd_jednostrana.pdf |title=Yugoimport SDPR Booklet |access-date=2018-04-04 |url-status=deviated |archive-url=https://web.archive.org/web/20180405040155/http://www.yugoimport.com/sites/default/files/knjizica_za_cargo_dvd_jednostrana.pdf |archive-date=2018-04-05}}</ref>
* C3 – Canadian C1 (M2A1) with lengthened, 33-caliber barrel
* KM101A1 – South Korean license of M101A1, 1977
* KH178 – South Korean 38 calibers variant, 1983
Carriage variants:
* M1920E – prototype, [[Gun carriage#Modern gun carriages|split trail]].<ref name="HOGG-42" />
* M1921E – prototype, [[Gun carriage#Modern gun carriages|box trail]].<ref name="HOGG-42" />
* M1925E – prototype, box trail.<ref name="HOGG-42" />
* T2, standardized as M1 – split trail, wooden wheels.<ref name="HOGG-42" />
* M1A1 – M1 carriages rebuilt with new wheels, brakes and other parts.<ref name="TM-9-2005" />
* T3 – prototype.<ref name="HOGG-42" />
* T4 – prototype.<ref name="HOGG-42" />
* T5, standardized as M2 (1940) – split trail, steel wheels with pneumatic tires.<ref name="HOGG-42" />
* M2A1 – electric brakes removed.<ref name="TM-9-1325">''Technical Manual TM 9-1325, 105&nbsp;mm Howitzers M2 and M2A1; Carriages M2A1 and M2A2; and Combat Vehicle Mounts M3 and M4''.</ref>
* M2A2 – modified shield.<ref name="TM-9-1325" />
* M2A2E2 – prototype with increased elevation to 70 degrees.
* XM124 & XM124E1 light auxiliary propelled howitzer – prototype (1962–1965) – produced by Sundstrand Aviation Corporation, who added an auxiliary drive system for local maneuverability (See also similar [[M114 155&nbsp;mm howitzer#Carriage variants|XM123 Medium Auxiliary Propelled 155&nbsp;mm Howitzer]] with similar configuration). The base XM124 provided two {{convert|20|hp|kW}}, air-cooled engines, while the XM124E1 provided a single {{convert|20|hp|kW}} engine and electric steering.
* M2A2 Terra Star auxiliary propelled howitzer – prototype (1969–1977) – Lockheed Aircraft Service Company added an auxiliary drive system and a [[Tri-star (wheel arrangement)|tri-star wheel system]] to the carriage of an M2A2 105&nbsp;mm light howitzer to provide local maneuverability. The last surviving example is at the [[Rock Island Arsenal]] Museum.
<gallery>
File:Canadian C3 howitzer March 3, 2009.jpg|Canadian soldiers fire a high explosive round with a C3 howitzer in 2009.
File:Royal Thai army M101.jpg|Royal Thai army M101 with new barrel.
File:XM124E2 Light Auxiliary-Propelled 105mm Howitzer.jpg|XM124E2 light auxiliary-propelled 105&nbsp;mm howitzer at the [[Rock Island Arsenal]] museum
File:M2A2 Terra Star 105mm Auxiliary Propelled Howitzer front quarter.jpg|The only surviving prototype M2A2 Terra Star auxiliary propelled howitzer at the [[Rock Island Arsenal]] Museum. Note the [[Tri-star (wheel arrangement)|tri-star wheel system]] and auxiliary drive system on the right trail leg.
File:105mm howitzer in Greenup, KY, US.jpg|[[Greenup, Kentucky]], US
File:21-24-151-howitzer.jpg|M101 A1 on display at [[Patriots Point|Patriots Point Naval and Maritime Museum]]
</gallery>

==Self-propelled mounts==
* [[M4 Sherman|Medium Tank M4A4E1]] – M2A1 in mount T70.{{sfn|Hunnicutt|1994|p=568}}
* Medium Tank M4(105), M4A3(105) – M4 in mount M52.{{sfn|Hunnicutt|1994|p=568}}
* [[M26 Pershing|Medium/Heavy Tank M45]] – M4 in mount M71.{{sfn|Hunnicutt|1971|p=233}}
* Experimental mount on Holt tractor –{{sfn|Hunnicutt|1992|p=317}}
* Experimental chassis designed by [[J Walter Christie]] – M1920.{{sfn|Hunnicutt|1992|p=317}}
* 105&nbsp;mm howitzer motor carriage T9 (based on Cletrac MG-2 tractor).{{sfn|Hunnicutt|1992|p=329}}
* [[T19 Howitzer Motor Carriage|105&nbsp;mm howitzer motor carriage T19]] (based on [[M3 Half-track|M3 halftrack]]) – M2A1.{{sfn|Hunnicutt|2001|p=236}}
* [[M7 Priest|105 mm howitzer motor carriage T32 / M7]] – M2A1.{{sfn|Hunnicutt|1994|p=568}}
* [[M37 105 mm howitzer motor carriage|105 mm howitzer motor carriage T76 / M37]] ([[M24 Chaffee|Light Tank M24]] chassis) – M4 in mount M5.{{sfn|Hunnicutt|1992|p=329}}
* 105&nbsp;mm amphibian gun motor carriage T87 (based on [[M18 Hellcat|GMC M18]] automotive components)  – T8
* 105&nbsp;mm howitzer motor carriage T88 (GMC M18 chassis) – M4 in mount M20.{{sfn|Hunnicutt|1992|p=334}}
* [[K105HT]] 105&nbsp;mm howitzer mounted on an armored 5-ton truck system built by [[Samsung Techwin]] for the [[Republic of Korea Army]] (initially called EVO-105)
* Vietnamese M101 howitzer mounted on an [[Ural-375]]D 6×6 truck.<ref>{{cite web |url=http://www.armyrecognition.com/may_2015_global_defense_security_news_uk/vietnam_has_developed_a_105mm_self-propelled_howitzer_on_a_ural-375d_chassis_20051531.html |title=Vietnam Has Developed a 105&nbsp;mm Self-Propelled Howitzer on a Ural-375D Chassis 20051531 – May 2015 Global Defense Security news UK – Defense Security global news industry army 2015 – Archive News year |website=www.armyrecognition.com |date=20 May 2015 |url-status=live |archive-url=https://web.archive.org/web/20150524021756/http://www.armyrecognition.com/may_2015_global_defense_security_news_uk/vietnam_has_developed_a_105mm_self-propelled_howitzer_on_a_ural-375d_chassis_20051531.html |archive-date=2015-05-24}}</ref>

==Ammunition==
The gun fired [[Shell (projectile)#Separate loading cased charge|semi-fixed]] ammunition, with 105&nbsp;mm Cartridge Case M14. The propelling charge consisted of a base charge and six incremental charges, forming seven charges from 1 (the smallest) to 7 (the largest). Use of M1 HE rounds prepared for the [[M3 howitzer|105 mm howitzer M3]] (same projectile and cartridge, but different propelling charge) was authorized.<ref name="TM-9-1901">''Technical Manual TM 9-1901, Artillery Ammunition'', p 167–178.</ref>

HEAT M67 Shell was originally designed as fixed round, with Cartridge Case M14 type II. It was later changed to semi-fixed type with the standard cartridge, but with non-adjustable propelling charge. For blank ammunition, a shorter Cartridge Case M15 with black powder charge was used.<ref name="TM-9-1901" />

{| class="wikitable"
|- style="vertical-align:top; text-align:center; "
|'''Type'''
|'''Model'''
|colspan="2"|'''Weight'''<br />'''Complete / Projectile'''
|'''Filler'''
|'''Muzzle velocity'''
|'''Range'''
|+Available ammunition{{sfn|Hunnicutt|2001|p=236}}<ref name="TM-9-1901" /><ref name="TM-9-1904">''Technical Manual TM 9-1904, Ammunition Inspection Guide'', p 471-484.</ref>
|- style="vertical-align:top; text-align:center;"
| style="text-align:left" | [[Shell (projectile)#High-explosive|HE]]
|  HE M1 Shell
|  {{convert|19.08|kg|lb|0|abbr=on}} 
| {{convert|14.97|kg|lb|0|abbr=on}}
|  [[Trinitrotoluene|TNT]] or 50/50 [[amatol]], {{convert|2.18|kg|lb|0|abbr=on}}
|  {{convert|472|m/s|abbr=on|disp=br() }}
|  {{convert|11,160|m|abbr=on|disp=br() }}
|- style="vertical-align:top; text-align:center;"
| style="text-align:left" | [[Shell (projectile)#High-explosive, anti-tank|HE-AT]]
|  HE-AT M67 Shell
|  {{convert|16.71|kg|lb|0|abbr=on}}
|  {{convert|13.25|kg|lb|0|abbr=on}}
|  [[Pentolite]], {{convert|1.33|kg|lb|0|abbr=on}}
|  {{convert|381|m/s|abbr=on|disp=br() }}
|  {{convert|7,854|m|abbr=on|disp=br() }}
|- style="vertical-align:top; text-align:center;"
| style="text-align:left" | [[Shell (projectile)#Smoke|Smoke]]
|  HC BE M84 Shell
|  {{convert|19.02|kg|lb|0|abbr=on}}
|  {{convert|14.91|kg|lb|0|abbr=on}}
|  [[Smoke-screen#Zinc chloride|Zinc chloride (HC)]]
|  {{convert|472|m/s|abbr=on|disp=br() }}
| {{convert|11,160|m|abbr=on|disp=br() }}
|- style="vertical-align:top; text-align:center;"
| style="text-align:left" | Smoke, colored
|  BE M84 Shell
|  {{convert|17.86–18.04|kg|lb|0|abbr=on}}
|
|  Smoke mixture
| 
| 
|- style="vertical-align:top; text-align:center;"
| style="text-align:left" | Smoke
|  WP M60 Shell
|  {{convert|19.85|kg|lb|0|abbr=on}}
| {{convert|15.56|kg|lb|0|abbr=on}}
|  [[Smoke-screen#Phosphorus|White phosphorus]], {{convert|1.84|kg|lb|0|abbr=on}}
|  {{convert|472|m/s|abbr=on|disp=br() }}
|  {{convert|11,110|m|abbr=on|disp=br() }}
|- style="vertical-align:top; text-align:center;"
| style="text-align:left" | Smoke
|  FS M60 Shell
|  {{convert|20.09|kg|lb|0|abbr=on}}
|
|  [[Sulfur trioxide]] in [[chlorosulfonic acid]], {{convert|2.09|kg|lb|0|abbr=on}}
| 
| 
|- style="vertical-align:top; text-align:center;"
| style="text-align:left" | [[Shell (projectile)#Chemical|Chemical]]
|  H M60 Shell
|  {{convert|19.43|kg|lb|0|abbr=on}}
|
|  [[Sulfur mustard|Mustard gas]], {{convert|1.44|kg|lb|0|abbr=on}}
| 
| 
|- style="vertical-align:top; text-align:center;"
| style="text-align:left" | Practice
|  Empty M1 Shell
| 
|
| 
|  {{convert|472|m/s|abbr=on|disp=br() }}
|  {{convert|11,160|m|abbr=on|disp=br() }}
|- style="vertical-align:top; text-align:center;"
| style="text-align:left" | Drill
|  Drill Cartridge M14
| 
|
| 
|  -
|  -
|- style="vertical-align:top; text-align:center;"
| style="text-align:left" | Blank
| 
| 
|
| 
|  -
|  -
|}

{| class="wikitable"
|- style="vertical-align:top; text-align:center; "
|+Armor penetration{{sfn|Hunnicutt|2001|p=236}}<ref>{{cite web|url=http://www.90thidpg.us/Reference/Manuals/FM%206-40.pdf|title=Field Artillery Gunnery |date=1 June 1945 |publisher=War Department |location=Washington DC |access-date=2017-06-13|archive-url=https://web.archive.org/web/20180727065342/http://www.90thidpg.us/Reference/Manuals/FM%206-40.pdf|archive-date=2018-07-27|url-status=live}}</ref><ref>{{cite web |url=http://bulletpicker.com/pdf/OP%201720,%20Shape%20Charge%20Ammunition.pdf |title=Shaped Charge Ammunition and Applications of Shaped Charges to Explosive Filled Ordnance |publisher=Department of the Navy |location=Washington DC |access-date=2017-06-13 |url-status=dead |archive-url=https://web.archive.org/web/20170517012725/http://bulletpicker.com/pdf/OP%201720,%20Shape%20Charge%20Ammunition.pdf |archive-date=2017-05-17 }}</ref>
|- style="vertical-align:top; text-align:center; "
! width="44%" |  Ammunition \ Distance
! width="14%" | 0
! width="14%" | {{convert|457|m|yd|0|abbr=on}}
! width="14%" | {{convert|914|m|yd|0|abbr=on}}
! width="14%" | {{convert|1,828|m|yd|0|abbr=on}}
|- style="vertical-align:top; text-align:center;"
| style="text-align:left" | HEAT M67 Shell (meet angle 0°)
| colspan="4" | {{convert|102-183|mm|in|0|abbr=on}}
|- style="vertical-align:top; text-align:center; "
| colspan="5" | '''Concrete penetration'''{{sfn|Hunnicutt|2001|p=236}}
|- style="vertical-align:top; text-align:center;"
| style="text-align:left" | HE M1 Shell (meet angle 0°)
|  {{convert|457|mm|ftin|0|abbr=on}}
|  {{convert|427|mm|ftin|0|abbr=on}}
|  {{convert|396|mm|ftin|0|abbr=on}}
|  {{convert|335|mm|ftin|0|abbr=on}}
|- style="vertical-align:top; text-align:center;"
| colspan="5" | Different methods of measurement were used in different countries / periods. Therefore, direct comparison is often impossible.
|}

==Operators==
[[File:Royal Thai Army firing M101 modified with extended range ammunition.jpg|thumb|Royal Thai Army firing extended range ammunition from M101 modified with LG1 L/33 cal barrel.]]
{{Div col|colwidth=20em}}
* {{ARG}}{{sfn|Military Balance 2016|p=377}}
* {{AUS}}
* {{AUT}}: ''Haubitze M1A2''{{citation needed|date=December 2020}}
* {{BHR}}
* {{BGD}} ''M101A1'' variant. 50 delivered in 1982. Status uncertain.<ref name="SIPRI">{{cite web |url=http://armstrade.sipri.org/armstrade/page/trade_register.php |title=Trade-Register-1971-2018.rft |website=Stockholm International Peace Research Institute |access-date=2019-04-21 |archive-date=14 April 2010 |archive-url=https://web.archive.org/web/20100414022558/http://armstrade.sipri.org/armstrade/page/trade_register.php |url-status=dead }}</ref>
* {{BEL}}<ref name="Wiener 1987">{{cite book|title=The armies of the NATO nations: Organization, concept of war, weapons and equipment|series=Truppendienst Handbooks Volume 3|year=1987|first=Friedrich |last=Wiener |pages=494–495|publisher=Herold Publishers|location=Vienna}}</ref>
* {{BEN}}{{sfn|Military Balance 2016|p=430}}
* {{BOL}}{{sfn|Military Balance 2016|p=380}}
* {{BIH}}
* {{BRA}}{{sfn|Military Balance 2016|pp=383-384}}
* {{BFA}}{{sfn|Military Balance 2016|p=432}}
* {{CAM}}
* {{CMR}}{{sfn|Military Balance 2016|p=434}}
* {{CAN}} Designated C3 - 93 in service <ref name="Military Balance 2025">{{cite book |title=The Military Balance |date=2025 |publisher=[[International Institute for Strategic Studies]] |isbn=978-1-041-04967-8}}</ref>{{rp|31}}
* {{CHA}}<ref name=trade>{{cite web |url=http://armstrade.sipri.org/armstrade/page/trade_register.php |title=Trade Registers |publisher=Armstrade.sipri.org |access-date=15 March 2019 |archive-url=https://web.archive.org/web/20110513073842/http://armstrade.sipri.org/armstrade/page/trade_register.php |archive-date=13 May 2011 |url-status=live }}</ref>
* {{CHL}}{{sfn|Military Balance 2016|p=387}}
* {{ROC}}{{sfn|Military Balance 2016|p=291}}
* {{COL}}{{sfn|Military Balance 2016|p=390}}
* {{HRV}}
* {{CYP}}
* {{DNK}}<ref name="Wiener 1987" />
* {{DOM}}{{sfn|Military Balance 2016|p=394}}
* {{ECU}}{{sfn|Military Balance 2016|p=396}}
* {{ETH}}
* {{SLV}}
* {{FRA}}<ref name="Wiener 1987" />
* {{GAB}}{{sfn|Military Balance 2016|p=446}}
* {{GER}} (Salute gun)
* {{GRC}}<ref name="Wiener 1987" />{{sfn|Military Balance 2016|p=104}}
* {{GTM}}{{sfn|Military Balance 2016|p=399}}
* {{HND}}
* {{IDN}}
* {{IRN}}<ref name="Razoux" />{{sfn|Military Balance 2016|p=328}}
* {{flag|Iraq|1963}}<ref name="Razoux">{{cite book|title=The Iran–Iraq War|first=Pierre |last=Razoux|translator-first=Nicholas|translator-last=Elliott|publisher=[[Harvard University Press]]|location=Cambridge, Massachusetts and London, England|date=2015|isbn=978-0-674-08863-4|pages=517, 523}}</ref>
* {{ITA}} in service between 1950 ed il 1976<ref>{{cite web |title=Obice da 105/22 a Traino Meccanico (USA) |url=https://www.esercito.difesa.it/storia/pagine/obice-da-10522-a-traino-meccanico-usa.aspx |publisher=Italian Army |access-date=8 December 2023}}</ref>
* {{JPN}} operated by 2000. A small number were produced domestically as Type 58. Some M2A1s remain in service for ceremonial purpose.<ref>{{cite web |url=http://rightwing.sakura.ne.jp/equipment/jgsdf/firearms/105howitzer-m2a1/105howitzer-m2a1.html |title=105 mm Howitzer M2A1 (Type 58) |access-date=2023-10-18 |work=Gallery Rightwing}}</ref>
* {{KOR}}<ref name="Korean War : Weapons of the United Nations" />{{sfn|Military Balance 2016|p=267}}
* {{flag|Khmer Republic}}
* {{flag|Laos}}<ref>{{cite book|title=The War in Laos, 1960–75|url=https://archive.org/details/warlaos00conb|url-access=limited|series=Men-at-Arms 217|first=Kenneth |last=Conboy|date=23 Nov 1989 |publisher=Osprey Publishing|isbn=978-0-85045-938-8|page=[https://archive.org/details/warlaos00conb/page/n13 15]}}</ref>{{sfn|Military Balance 2016|p=271}}
* {{flag|Lebanon}}{{sfn|Military Balance 2016|p=340}}
* {{flag|Liberia}}<ref>{{cite web|url=http://armstrade.sipri.org/armstrade/page/trade_register.php|title=Trade Registers|website=armstrade.sipri.org|url-status=live |archive-url=https://web.archive.org/web/20100414022558/http://armstrade.sipri.org/armstrade/page/trade_register.php|archive-date=2010-04-14}}</ref>
* {{LTU}} – 54 acquired from Denmark in 2002. At least 18 units were donated to Ukraine in 2022.{{sfn|Military Balance 2016|p=116}}<ref>{{Cite web |last=Axe |first=David |title=Ukraine's World War II-Vintage Howitzers Still Work Just Fine |url=https://www.forbes.com/sites/davidaxe/2022/11/28/ukraines-world-war-ii-vintage-howitzers-still-work-just-fine/ |access-date=2023-11-27 |website=Forbes |language=en}}</ref>
* {{MKD}}<ref>{{cite magazine|title=Macedonia's Weaponry: A New Nation Re-Arms and Fights|first=Rob|last=Krott|url=https://www.smallarmsreview.com/display.article.cfm?idarticles=2122|journal=Small Arms Review|volume=7|issue=1|date=October 2003|access-date=2019-03-30|archive-url=https://web.archive.org/web/20190330233215/https://www.smallarmsreview.com/display.article.cfm?idarticles=2122|archive-date=2019-03-30|url-status=live}}</ref>
* {{MAS}}
* {{flag|Mauritania}}{{sfn|Military Balance 2016|p=343}}
* {{MDG}}{{sfn|Military Balance 2016|p=454}}
* {{MEX}}{{sfn|Military Balance 2016|p=404}}
* {{MAR}}{{sfn|Military Balance 2016|p=345}}
* {{MOZ}}{{sfn|Military Balance 2016|p=458}}
* {{MMR}} – 242 in service{{sfn|Military Balance 2016|p=276}}
* {{NLD}}<ref name="Wiener 1987" />
* {{NZL}}
* {{NIC}}
* {{NOR}}<ref name="Wiener 1987" />
* {{PAK}}{{sfn|Military Balance 2016|p=280}}
* {{PRY}}{{sfn|Military Balance 2016|p=408}}
* {{PER}}{{sfn|Military Balance 2016|p=410}}
* {{PHL}}{{sfn|Military Balance 2016|pp=284-285}}
* {{POR}}<ref name="Wiener 1987" />{{sfn|Military Balance 2016|p=130}}
* {{flag|Rhodesia}}<ref name="Keegan">John Keegan, page 589 ''World Armies'', {{ISBN|0-333-17236-1}}</ref>
* {{flag|Rwanda|1962}}<ref name="Rwanda">{{cite news|title=Rwanda: selon les services de renseignementfrançais, Les rebelles bénéficieraient du soutien de l'armée ougandaise |url=http://francegenocidetutsi.org/SoutienOugandaisRebellesLeMonde17fevrier1993.pdf|first=Jacques |last=Isnard|newspaper=Le Monde|date=17 February 1993 |page=5|language=fr}}</ref>
* {{SAU}}{{sfn|Military Balance 2016|p=351}}
* {{SEN}}{{sfn|Military Balance 2016|p=464}}
* {{RSA}}<ref>{{cite web|url=http://www.defenceweb.co.za/index.php?option=com_content&view=article&id=13537:fact-file-g6-l45-self-propelled-towed-gun-howitzer-&catid=79:fact-files&Itemid=159|title=Fact file: G6 L45 self-propelled towed gun-howitzer – defenceWeb|first=Leon|last=Engelbrecht|website=www.defenceweb.co.za|date=10 February 2011 |url-status=live|archive-url=https://web.archive.org/web/20140109033607/http://www.defenceweb.co.za/index.php?option=com_content&view=article&id=13537:fact-file-g6-l45-self-propelled-towed-gun-howitzer-&catid=79:fact-files&Itemid=159|archive-date=2014-01-09}}</ref>
* {{ESP}}<ref name="Wiener 1987" />
* {{SDN}}{{sfn|Military Balance 2016|p=471}}
* {{SUI}} (Avalanche control)<ref>{{cite web|url=https://www.youtube.com/watch?v=Pm6HmPuLL70|title=Avalanche control brings out the Howitzer|date=11 September 2019 |publisher=[[YouTube]]}}</ref>
* {{THA}}{{sfn|Military Balance 2016|p=293}}
* {{TGO}}
* {{TUN}}{{sfn|Military Balance 2016|p=356}}
* {{TUR}}<ref name="Wiener 1987" />{{sfn|Military Balance 2016|p=148-150}}
* {{UKR}}<ref>{{cite web|title=Lithuania sends howitzers from its reserve to Ukraine|url=https://www.lrt.lt/en/news-in-english/19/1775591/lithuania-sends-howitzers-from-its-reserve-to-ukraine|date=8 September 2022|access-date=15 September 2022|website=LRT}}</ref>
* {{USA}}{{sfn|Military Balance 2016|p=44}} (Avalanche control and Salute gun)
* {{URY}}{{sfn|Military Balance 2016|p=414}}
* {{VEN}}{{sfn|Military Balance 2016|p=416}}
* {{VIE}}{{sfn|Military Balance 2016|p=297}}
**{{flag|South Vietnam}}
* {{YEM}}
{{div col end}}

==See also==
* [[List of U.S. Army weapons by supply catalog designation]] (SNL C-21)
* [[M3 howitzer]] – Shortened barrel variant of M2 howitzer.
* [[M102 howitzer]] – The US partial replacement for M101 howitzer.
* [[KH178 105 mm towed howitzer]] – South Korean 38 calibers variant of M101A1.
* [[Indian Field Gun]] – Indian 105&nbsp;mm howitzer.
* [[L118 light gun]] – British 105&nbsp;mm howitzer.
* [[M119 howitzer]] – The US license of L118, replacement for M101 and M102 howitzer.
* [[GIAT LG1]] – French 105&nbsp;mm howitzer.

==Notes==
{{Reflist}}

==References==
* {{cite book
  | last=Hogg
  | first=Ian V.
  | author-link=Ian V. Hogg
  | title=Allied Artillery of World War Two
  | publisher=Crowood Press, Ramsbury
  | year=1998
  | isbn=1-86126-165-9
}}
* {{cite book
  | last=Hunnicutt
  | first=R. P.
  |authorlink=R. P. Hunnicutt
  | title=Pershing: A History of the Medium Tank T20 Series
  | publisher=Feist Publications
  | year=1971
}}
* {{cite book
  | last=Hunnicutt
  | first=R. P.
  |authorlink=R. P. Hunnicutt
  | title=Stuart: A History of the American Light Tank
  | publisher=Presidio Press
  | year=1992
  | isbn=0-89141-462-2
}}
* {{cite book
  | last=Hunnicutt
  | first=R. P.
  |authorlink=R. P. Hunnicutt
  | title=Sherman: A History of the American Medium Tank
  | publisher=Presidio Press
  | year=1994
  | isbn=0-89141-080-5
}}
* {{cite book
  | last=Hunnicutt
  | first=R. P.
  |authorlink=R. P. Hunnicutt
  | title=Half-Track: A History of American Semi-Tracked Vehicles
  | publisher=Presidio Press
  | year=2001
  | isbn=0-89141-742-7
}}
* {{cite book
  | title=Technical Manual TM 9-1325, 105&nbsp;mm Howitzers M2 and M2A1; Carriages M2A1 and M2A2; and Combat Vehicle Mounts M3 and M4
  | publisher=War Department, 1944
}}
* {{cite book
  | title=Technical Manual TM 9-1901, Artillery Ammunition
  | publisher=War Department, 1944
}}
* {{cite book
  | title=Technical Manual TM 9-1904, Ammunition Inspection Guide
  | publisher=War Department, 1944
}}
* {{cite book
  | title=Technical Manual TM 9-2005 volume 3, Infantry and Cavalry Accompanying Weapons
  | publisher=War Department, 1942
}}
* {{cite book|title=The Military Balance 2016|date=February 2016|volume=116|isbn=978-1-85743-835-2 |publisher=Routlegde|ref={{harvid|Military Balance 2016}}|author=International Institute for Strategic Studies|author-link=International Institute for Strategic Studies}}

==External links==
{{Commons|M101 105&nbsp;mm howitzer}}
* [https://books.google.com/books?id=-iYDAAAAMBAJ&dq=popular+science+cannon&pg=PA54 ''Two Guns For One'', November 1942, Popular Science] one of the earliest detailed public article published on the M101 Howitzer
* [http://www.fas.org/man/dod-101/sys/land/m101a1.htm FAS Military Analysis Network]

{{WWIIUSGuns}}
{{Canadian Forces Land Force Command}}
{{Authority control}}

[[Category:105&nbsp;mm artillery]]
[[Category:World War II howitzers]]
[[Category:Field artillery of the Cold War]]
[[Category:World War II artillery of the United States]]
[[Category:Cold War artillery of the United States]]
[[Category:Artillery of the United States]]
[[Category:Weapons and ammunition introduced in 1941]]