View source for M19A1

{{About
| about = American SPAA '''{{PAGENAME}}'''
| usage = the Japanese variant
| link = M19A1 (Japan)
}}
{{Specs-Card
|code=us_m19
|images={{Specs-Card-Image|GarageImage_{{PAGENAME}}.jpg|ArtImage_{{PAGENAME}}.png}}
}}

== Description ==
<!-- ''In the description, the first part should be about the history of the creation and combat usage of the vehicle, as well as its key features. In the second part, tell the reader about the ground vehicle in the game. Insert a screenshot of the vehicle, so that if the novice player does not remember the vehicle by name, he will immediately understand what kind of vehicle the article is talking about.'' -->
The '''M19 Multiple Gun Motor Carriage (MGMC)''' is a self-propelled anti-aircraft gun mounted on the [[M24|M24 light tank]] chassis used by the U.S. Army during World War II. It was armed with two 40 mm M2A1 Bofors autocannons. It was manufactured near the end of 1944 by Cadillac and Massey Ferguson of Canada. Although the vehicles were built during World War II, they did not become operational until the war was over. They saw their first combat in the Korean War against North Korean forces in 1950. The M19A1 MGMC is an improved design, rather than a separate variant, that includes an auxiliary engine and generator to power the main armament when the main engine is shut down, as well as fixtures for carrying two spare cannon barrels.

Introduced in [[Update 1.45 "Steel Generals"]], the M19 MGMC is a versatile vehicle. The 40 mm M2A1 Bofors autocannons can penetrate some lightly armoured vehicles and have enough destructive capability to bring down aircraft. There are two types of ammunition belts: armour-piercing and high-explosive. It can be employed for flanking maneuvers early in the conflict, given its exceptional mobility. It is crucial to remember, though, that the majority of crews are completely exposed, with ammunition placed all around the turret.

== General info ==
=== Survivability and armour ===
{{Specs-Tank-Armour}}
<!-- ''Describe armour protection. Note the most well protected and key weak areas. Appreciate the layout of modules as well as the number and location of crew members. Is the level of armour protection sufficient, is the placement of modules helpful for survival in combat? If necessary use a visual template to indicate the most secure and weak zones of the armour.'' -->
'''Armour type:'''

* Rolled homogeneous armour (hull, turret)

{| class="wikitable"
|-
! Armour !! Front (Slope angle) !! Sides !! Rear !! Roof
|-
| Hull || 12.7 mm (59°) ''Upper glacis'' <br> 12.7 mm (45°) ''Lower glacis'' || 12.7 mm (11°) || 12.7 mm || 12.7 mm
|-
| Turret || 12.7 mm (cylindrical) ''Gun shield - lower part'' <br> 12.7 mm (spherical) ''Gun shield - upper part'' || 8 mm (cylindrical) <br> 8 + 12.7 mm (cylindrical) ''Turret base'' || 8 mm (cylindrical) <br> 8 + 12.7 mm (cylindrical) ''Turret base''
!
|-
|}

'''Notes:'''

* Suspension wheels are 10 mm thick while tracks are 15 mm thick.

The {{PAGENAME}} is so lightly armoured that it is very vulnerable to nearby ammorack detonations, bomb blasts and even heavy MG fire can reliably penetrate the vehicle from beyond 1,000 m.
As the {{PAGENAME}} has an open-topped turret, gun servants are also very exposed to MG fire, artillery strikes and plane strafings.

=== Mobility ===
{{Specs-Tank-Mobility}}
<!-- ''Write about the mobility of the ground vehicle. Estimate the specific power and manoeuvrability, as well as the maximum speed forwards and backwards.'' -->

{{tankMobility|abMinHp= 420|rbMinHp= 262}}

As a light vehicle, the {{PAGENAME}} is agile. While it has a high top speed, the acceleration is quite slow: expect a cruise speed around 40 km/h instead. The reverse speed is very high, allowing you to pull out of dangerous situations quickly. The lack of neutral steering makes turning on the spot slow (3 km/h): make sure to build a little speed before turning and you'll turn faster (7 km/h). If you need to quickly turn your hull on the spot towards flanking enemies, privilege the reverse gear (-6 km/h).

The offroad mobility is good: the {{PAGENAME}} reaches 17 km/h when fording, 19 km/h when driving uphill with some speed built-up and a mere 12 km/h uphill from a stop start. The wide tracks combined to the light weight of the vehicle grant the {{PAGENAME}} a good mobility on hard (solid ground, roads) and soft terrain (mud, snow, sand). Light obstacles (fences and bushes) are not a problem but medium to large obstacles (posts, trees, concrete blocks and parked vehicles) will reduce your mobility: avoid them.

=== Modifications and economy ===
{{Specs-Economy}}

== Armaments ==
{{Specs-Tank-Armaments}}
=== Main armament ===
{{Specs-Tank-Weapon|1}}
<!-- ''Give the reader information about the characteristics of the main gun. Assess its effectiveness in a battle based on the reloading speed, ballistics and the power of shells. Do not forget about the flexibility of the fire, that is how quickly the cannon can be aimed at the target, open fire on it and aim at another enemy. Add a link to the main article on the gun: <code><nowiki>{{main|Name of the weapon}}</nowiki></code>. Describe in general terms the ammunition available for the main gun. Give advice on how to use them and how to fill the ammunition storage.'' -->
{{main|Dual Automatic Gun M2 (40 mm)}}

{| class="wikitable" style="text-align:center" width="100%"
|-
! colspan="6" | [[Dual Automatic Gun M2 (40 mm)|40 mm Dual Automatic Gun M2]] (x2) || colspan="5" | Turret rotation speed (°/s) || colspan="4" | Reloading rate (seconds)
|-
! Mode !! Capacity (Belt) !! Fire rate !! Vertical !! Horizontal !! Stabilizer
! Stock !! Upgraded !! Full !! Expert !! Aced
! Stock !! Full !! Expert !! Aced
|-
! ''Arcade''
| rowspan="2" | 352 (8) || rowspan="2" | 120 || rowspan="2" | -5°/+85° || rowspan="2" | ±180° || rowspan="2" | N/A || 35.2 || 48.8 || 59.2 || 65.5 || 69.7 || rowspan="2" | 0.65 || rowspan="2" | 0.58 || rowspan="2" | 0.53 || rowspan="2" | 0.50
|-
! ''Realistic''
| 23.8 || 28.0 || 34.0 || 37.6 || 40.0
|-
|}

The 40 mm gun stays reliably accurate until 1,000 m distance. Beyond 1,500 m the loss of accuracy becomes a real handicap.
The shortness of the gun is mitigated by the high rate of fire and the fact that targeted aircraft are bigger than an average ground vehicle. Your ideal engagement window is between 1,000 and 1,500 m for aircraft. The high muzzle velocity of your shells grants you pretty flat firing trajectories and thus helps fire at fast-moving targets from a distance. As your shells weigh the same, your different belts offer the same firing arc.

The turret traverse speed is very high, allowing you to track any aircraft flying right by you. The gun elevation is also very good, almost allowing vertical fire. The depression angle is poor but not often used. The recoil is minimal and barely impacts your targeting. The reload time between clips is very short: under 1 second. While lacking a stabilizer, the M19 still can reliably fire on the move at targets under 700 m distance.

The gun overheats after  in 20 seconds of uninterrupted fire and is forced into a cooldown phase of 10 seconds during which you can't shoot.
To keep the gun from overheating, privilege firing by bursts instead of continuous fire with small pauses between shots. The overheating is displayed in-game by 4 red quadrants around your sight gradually filling up as you gun temperature rises. Always keep it from reaching the 3rd quadrant.

==== Ammunition ====

* '''Default:''' {{Annotation|AP-T|Armour-piercing tracer}}{{-}}{{Annotation|FI-T*|Fragmentation incendiary tracer (self-destroying)}} - The belt composition means that 50% of the shells (FI-T*) are useless against tanks. However, this belt is reliable against open-topped or lightly armoured targets like SPAA vehicles as well as against planes.

* '''Mk.II:''' {{Annotation|FI-T*|Fragmentation incendiary tracer (self-destroying)}} - This belt does little damage against armoured targets and should be used especially against aircraft or open-topped vehicles. The high-explosive filler is deadly to crew members.

* '''M81A1:''' {{Annotation|AP-T|Armour-piercing tracer}} - This belt offers excellent damage against tanks, especially at close range. While the damage effects post-penetration can be quite poor, the rapid fire from the autocannon can remedy this problem by following up quickly with another penetrating shot. In close combat, these shells should be used against modules and crew member to make the most of each shell. With luck and a good side shot, the shells can even kill vehicles like the [[VK 3002 (M)]].

{{:Dual Automatic Gun M2 (40 mm)/Ammunition|Mk.II, M81A1}}

==== [[Ammo racks]] ====
[[File:Ammoracks_{{PAGENAME}}.png|right|thumb|x250px|[[Ammo racks]] of the {{PAGENAME}}]]
<!-- '''Last updated: 2.25.1.70''' -->
{| class="wikitable" style="text-align:center"
|-
! Full<br>ammo
! 1st<br>rack empty
! 2nd<br>rack empty
! 3rd<br>rack empty
! 4th<br>rack empty
! 5th<br>rack empty
! 6th<br>rack empty
! 7th<br>rack empty
|-
| '''44''' || 40&nbsp;''(+4)'' || 36&nbsp;''(+8)'' || 32&nbsp;''(+12)'' || 30&nbsp;''(+14)'' || 26&nbsp;''(+18)'' || 22&nbsp;''(+22)'' || 18&nbsp;''(+36)''
|-
! 8th<br>rack empty
! 9th<br>rack empty
! 10th<br>rack empty
! 11th<br>rack empty
! 12th<br>rack empty
! 13th<br>rack empty
! Visual<br>discrepancy
!
|-
| 16&nbsp;''(+28)'' || 12&nbsp;''(+32)'' || 8&nbsp;''(+36)'' || 4&nbsp;''(+40)'' || 2&nbsp;''(+42)'' || 0&nbsp;''(+44)'' || Yes
!
|-
|}

'''Notes''':

* Ammunition is modelled as 44 clips of 8 rounds
* The visual discrepancy concerns the total number of rounds: 312 rounds are modeled but you can pack 352 rounds.

== Usage in battles ==
<!-- ''Describe the tactics of playing in the vehicle, the features of using vehicles in the team and advice on tactics. Refrain from creating a "guide" - do not impose a single point of view but instead give the reader food for thought. Describe the most dangerous enemies and give recommendations on fighting them. If necessary, note the specifics of the game in different modes (AB, RB, SB).'' -->
With the Dual 40 mm Bofors the M19 has an excellent weapon against [[:Category:Bombers|bombers]] and [[:Category:Attackers|armoured attackers]]. The ammo is limited though, so reserve the fire for certain hits. Against fighters, the same tactic should be applied.

Due to its poor rate of fire and therefore fire density, it's best to concentrate fire at a spot the plane is expected to fly towards whilst leading to compensate, bursts should be short and constant adjustments should be made. Thanks to its large calibre and continuous fire, the M19A1 can be used to take out long range bombers at high altitudes that .50 cal and 20 mm rounds may fail to reach.

The M19A1 can also be used to impressive effect against ground vehicles at its BR, particularly when facing Germany, whose lineups around this BR will include the [[Pz.IV F2]], [[Pz.IV H]], and [[Sd.Kfz.234/2]], along with the [[Marder III H]] and [[Sturer Emil]], among other open-topped tank destroyers. Against the USSR, 'brawling' anti-tank usage is not recommended as vehicles like the [[T-34 (1942)]], [[SU-152]], and [[KV-1S]] will easily bounce your shells and obliterate you. However, flanking maneouvres with the vehicle can yield incredibly impressive results, even against the aforementioned Russian vehicles. Due to the simple fact that the next SPAA most players are likely to research is at 7.7, this SPAA will likely be brought up to those BRs. Fear not, as there are still lightly armoured vehicles around. [[PT-76 (Family)|PT-76]]<nowiki/>s, often being incredibly annoying to heavily armoured vehicles with their HEAT-FS rounds, can be easily obliterated with a couple of hits. The same goes for the [[BTR-ZD]] and other SPAAs, and the [[Nashorn]], surprisingly.

=== Pros and cons ===
<!-- ''Summarise and briefly evaluate the vehicle in terms of its characteristics and combat effectiveness. Mark its pros and cons in a bulleted list. Try not to use more than 6 points for each of the characteristics. Avoid using categorical definitions such as "bad", "good" and the like - use substitutions with softer forms such as "inadequate" and "effective".'' -->

'''Pros:'''

* Good mobility
* Powerful 40 mm FI-T shells, can decimate/critically damage aircraft
* Strong AP rounds with high penetration statistics
* Reloads in 0.6 seconds, quasi-continuous fire
* High ammo count 

'''Cons:'''

* Open-topped, exposing loaders and gunners
* Little armour
* Exposed ammo rack
* Underwhelming anti-air accuracy
* Gun overheats when firing continuously

== History ==
<!-- ''Describe the history of the creation and combat usage of the vehicle in more detail than in the introduction. If the historical reference turns out to be too long, take it to a separate article, taking a link to the article about the vehicle and adding a block "/History" (example: <nowiki>https://wiki.warthunder.com/(Vehicle-name)/History</nowiki>) and add a link to it here using the <code>main</code> template. Be sure to reference text and sources by using <code><nowiki><ref></ref></nowiki></code>, as well as adding them at the end of the article with <code><nowiki><references /></nowiki></code>. This section may also include the vehicle's dev blog entry (if applicable) and the in-game encyclopedia description (under <code><nowiki>=== In-game description ===</nowiki></code>, also if applicable).'' -->
===Development===
The development of this vehicle began from the T65 project. The T65 was classified as the ''40 mm Gun Motor Carriage T65'' and was based off the chassis of the [[M5A1|M5 Stuart]] as requested by US Army Armored Force for a light anti-aircraft vehicle. The T65 was a successful vehicle and went on for about 1,000 units produced, however, it stopped because the production line for the Stuart chassis was phased out as well. As a replacement, the Armored Force peered into the new light tank entering production, the [[M24|M24 Chaffee]], as the basis of their new light anti-aircraft vehicle. This project was called the ''T65E1'' and was being developed at the same time with the M24 (still in development as the T24). The layout for the T65E1 on the new chassis was similar to the one used with Stuart's chassis, with the gun turret at the rear and engine at the middle, and only a few changes were made like changing the original vertical gun shield into an angular one.

The T65E1 was accepted in May 1944 and designated as the '''Twin Gun Motor Carriage M19'''. An order of 904 of these vehicles was sent to Cadillac, but production didn't start until August and the factory was only able to make 285 units before the war ended due to diversion in parts to creating full M24 Chaffees. An upgrade made during its production life was designated the '''M19A1''' and had an auxiliary engine and generator to operate the 40 mm cannons in case the main engine is disabled, plus an extra compartment to hold two spare barrels for the gun should they be damaged or overheated.

===Combat usage===
The M19 TGMCs that were produced were sent to Europe and used by the US Army. However, by the time the M19 was available for use, the German Luftwaffe had been decimated by the Allied air superiority, thus the M19 use as an anti-aircraft gun has been diminished greatly. The M19, like its many anti-aircraft vehicle designs made before it, found great service as an assault gun, where its 40 mm twin cannons can deliver much more firepower than its predecessors with either only .50 calibre machine guns ([[M16 MGMC|M16 MGMC]]), or a 37 mm autocannon ([[M15A1 CGMC|M15 CGMC]]). The M19 was never exported to America's allies in the Lend-Lease Act, and not even after the war with the Military Aid Program. Despite that, the M19 still saw use in America up to the Korean War for nearly the same purposes it was given for in World War II as a ground support weapon. It was used as a defensive turret against charging North Korean and Chinese forces when they try to overrun infantry positions, to which it served with devastating effect. Its effect against enemy aircraft is dubious during the war.

When the M24 Chaffee and its chassis derivatives were finally phased out of service in 1956 for newer tanks in production, the M19 was no exception. However, the M19 40 mm turrets were removed from the chassis and was simply put onto the next light tank chassis that was to take over the role the M24 Chaffee was built for. This light tank was the [[M41A1|M41 Walker Bulldog]] and the M19 turret-mounted chassis was named the [[M42|M42 Duster]].

{{break}}
{{Navigation-Start|{{Annotation|Archive of the in-game description|An archive of the historical description of the vehicle that was presented in-game prior to Update 1.55 'Royal Armour'}}}}
{{Navigation-First-Simple-Line}}
Combat experience in 1941-1942 showed that the troops needed a mobile anti-aircraft system capable of escorting mechanized columns and protecting against enemy aircraft. Development of the new vehicle began in 1942. The first prototype of the T65 self-propelled artillery piece was created using the M5A1 light tank chassis, though it was replaced during trials with the M24 light tank's more modern version.

The hull's nose section was home to the transmission and the driver's compartment, in which the driver (left) and commander (right) were located. The roof of the driver's compartment had hatches and periscopes, while the engine was located in the center section. The battle compartment was in the rear section, on the roof of which was an open-air turret system mounted in the front with two electrically fired 40 mm Bofors automatic cannons. The turret was rotated using a manually operated electrohydraulic actuator. Ammunition included high-explosive and incendiary rounds, while the crew was armed with two 11.43 mm Thompson submachine guns and four 7.62 mm carbines.

By September 1945 Cadillac and Masse-Harris had produced 285 (300 by other calculations) units, and by the end of 1945 they had begun to join tank divisions. They saw combat in the Korean War from 1950 to 1953. The primary goal of the M19 was to fight off land targets, something they were good at through the entire campaign, and they remained in the US army until 1956.
{{Navigation-End}}

== Media ==
<!-- ''Excellent additions to the article would be video guides, screenshots from the game, and photos.'' -->

;Skins

* [https://live.warthunder.com/feed/camouflages/?vehicle=us_m19 Skins and camouflages for the {{PAGENAME}} on live.warthunder.com.]

;Videos
{{Youtube-gallery|4ZWGcJAhe78|'''How to destroy tanks with low penetrating shells?''' - ''HowToPlay1337''}}

== See also ==
<!-- ''Links to the articles on the War Thunder Wiki that you think will be useful for the reader, for example:''
* ''reference to the series of the vehicles;''
* ''links to approximate analogues of other nations and research trees.'' -->

;Vehicles equipped with the same chassis

* [[M24 (Family)]]

;Other vehicles of similar configuration and role

* [[M42 Duster (Family)]]

== External links ==
<!-- ''Paste links to sources and external resources, such as:''
* ''topic on the official game forum;''
* ''other literature.'' -->

* [[wt:en/devblog/current/694|[Development] Steel Generals: M19]]
* [[wt:en/devblog/current/724|[Development] Developers about the M19]]
* [[wikipedia:M19_Multiple_Gun_Motor_Carriage|[Wikipedia] M19 Multiple Gun Motor Carriage]]
* [https://www.militaryfactory.com/armor/detail.asp?armor_id=323 <nowiki>[Military Factory]</nowiki> M19 Gun Motor Carriage (M19 Twin 40mm)]

{{USA anti-aircraft vehicles}}