View source for IS-4M

{{Specs-Card|code=ussr_is_4m}}

== Description ==
<!--''In the description, the first part needs to 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 the screenshot of the vehicle. If the novice player does not remember the vehicle by name, they will immediately understand what kind of vehicle it is talking about.''-->
[[File:GarageImage_{{PAGENAME}}.jpg|420px|thumb|left]]
{{break}}
The '''{{Specs|name}}''' is a rank {{Specs|rank}} Soviet heavy tank {{Battle-rating}}. It was introduced during the closed beta testing for Ground Forces before Update 1.41. 

== General info ==
=== Survivability and 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 roof, Hatch roof)
* Cast homogeneous armour (Turret)

{| class="wikitable"
|-
! Armour !! Front !! Sides !! Rear !! Roof
|-
| Hull || 140 mm (62°) ''Front glacis'' <br> 160 mm (40°) ''Lower glacis'' <br> 160 mm (34-77°) ''Driver's port'' <br> 40 mm (44-87°) ''Top of Driver's port''|| 160 mm (30-53°) ''Top'' <br> 160 mm ''Middle'' <br> 30 mm (61°) ''Bottom'' || 100 mm (37°) ''Top'' <br> 30 mm (80°) ''Middle'' <br> 100 mm (31-39°) ''Bottom'' || 30 mm 
|-
| Turret || 200-250 mm (2-89°) ''Turret front'' <br> 200 mm (0-65°) , 170 + 250 mm (2-61°) ''Gun mantlet''  || 200 mm (3-40°) || 150 (62-72°) ''Top'' <br>  170 mm (21-49°) ''Bottom'' || 30 mm ''Front, Hatch roof, Ventilators'' <br> 50 mm ''Front sides'' <br> 170 mm ''Center''
|-
|}
'''Notes:'''

* Suspension wheels are 20 mm thick, torsion bars are 10 mm thick, and tracks are 30 mm thick.

=== Mobility ===
<!--''Write about the mobility of the ground vehicle. Estimate the specific power and maneuverability as well as the maximum speed forward and backward.''-->
{| class="wikitable" style="text-align:center"
|-
! colspan="3" | Mobility characteristic
|-
! Weight (tons)
! colspan="1" | Add-on Armour<br>weight (tons)
! colspan="1" | Max speed (km/h)
|-
| rowspan="2" | 60.0 || colspan="1" rowspan="2" | N/A || colspan="1" | 45 (AB) 
|-
|43 (RB/SB)
|-
! colspan="3" | Engine power (horsepower)
|-
! colspan="1" | Mode
!Stock
!Upgraded
|-
|''Arcade''
|968
|___
|-
|''Realistic/Simulator''
|663
|750
|-
! colspan="3" | Power-to-weight ratio (hp/ton)
|-
! colspan="1" | Mode
!Stock
!Upgraded
|-
|''Arcade''
|16.13
|__.__
|-
|''Realistic/Simulator''
|11.05
|12.50
|-
|}

== Armaments ==
=== Main armament ===
<!--''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|D-25T (122 mm)}}

{| class="wikitable" style="text-align:center"
|-
! colspan="6" | [[D-25T (122 mm)|122 mm D-25T]]
|-
! colspan="3" rowspan="1" style="width:5em" |Capacity
! rowspan="1" | Vertical <br> guidance
! rowspan="1" | Horizontal <br> guidance
! rowspan="1" | Stabilizer
|-
| colspan="3" | 30 || -3°/+19° || ±180° || N/A
|-
! colspan="6" | Turret rotation speed (°/s)
|-
! style="width:4em" |Mode
! style="width:4em" |Stock
! style="width:4em" |Upgraded
! style="width:4em" |Prior + Full crew
! style="width:4em" |Prior + Expert qualif.
! style="width:4em" |Prior + Ace qualif.
|-
| ''Arcade'' ||9.4||13.0|| __.__ || __.__ || __.__
|-
| ''Realistic'' ||6.9||8.1|| __.__ || __.__ || __.__
|-
! colspan="4" | Reloading rate (seconds)
|-
! colspan="1" style="width:4em" |Stock
! colspan="1" style="width:4em" |Prior + Full crew
! colspan="1" style="width:4em" |Prior + Expert qualif.
! colspan="1" style="width:4em" |Prior + Ace qualif.
|-
| 27.1 || __.__ || __.__ || 20.8
|-
|}

===== Ammunition =====
{| class="wikitable sortable" style="text-align:center" width="100%"
! colspan="8" | Penetration statistics
|-
! rowspan="2" data-sort-type="text" | Ammunition
! rowspan="2" class="unsortable" | Type of <br /> warhead
! colspan="6" | '''Penetration''' '''''in mm''''' '''@ 90°'''
|-
! 10m
! 100m
! 500m
! 1000m
! 1500m
! 2000m
|-
| BR-471 || APHE || 204 || 200 || 182 || 162 || 144 || 128 
|-
| BR-471B || APHEBC || 205 || 202 || 191 || 178 || 165 || 154 
|- 
| BR-471D || APCBC|| 229 || 227 || 214 || 199 || 186 || 173
|- 
| OF-471 || HE || 45 || 45 || 44 || 43 || 42 || 42 
|- 
|}
{| class="wikitable sortable" style="text-align:center" width="100%"
! colspan="11" | Shell details
|-
! rowspan="2" data-sort-type="text" | Ammunition
! rowspan="2" class="unsortable" | Type of <br /> warhead
! rowspan="2" |Velocity <br /> in m/s
! rowspan="2" |Projectile<br />Mass in kg
! rowspan="2" | ''Fuse delay''
''in m:''
! rowspan="2" | ''Fuse sensitivity''
''in mm:''
! rowspan="2" | ''Explosive Mass in g<br /> (TNT equivalent):''
! rowspan="2" | ''Normalization At 30° <br> from horizontal:''
! colspan="3" | ''Ricochet:''
|-
! 0%
! 50%
! 100%
|-
| BR-471 || APHE || 795 || 25 || 1.2 || 19 || 272 || -1° || 47° || 60° || 65°
|-
| BR-471B || APHEBC || 795 || 25 || 1.2 || 19 || 272 || +4° || 48° || 63° || 71°
|- 
| BR-471D || APCBC || 800 || 25 || 1.2 || 19 || 212.5 || +4° || 48° || 63° || 71°
|- 
| OF-471 || HE || 800 || 25 || 0.1 || 0.1 || 3,600 || +0° || 79° || 80° || 81°
|- 
|}

===== [[Ammo racks|Ammo racks]] =====
[[File:Ammoracks_{{PAGENAME}}.png|right|thumbnail|x250px|Ammo racks of the {{PAGENAME}}.]]
{| class="wikitable sortable" style="text-align:center"
|-
! class="wikitable unsortable" |Full<br /> ammo
! class="wikitable unsortable" |Ammo<br />Part
! class="wikitable unsortable" |1st<br />  rack empty
! class="wikitable unsortable" |2nd<br />  rack empty
! class="wikitable unsortable" |3rd<br />  rack empty
! class="wikitable unsortable" |4th<br />  rack empty
! class="wikitable unsortable" |5th<br />  rack empty
! class="wikitable unsortable" |6th<br />  rack empty
! class="wikitable unsortable" |Visual<br /> discrepancy
|-
|| '''30''' || style="text-align:right" | ''Projectiles''<br />''Propellants'' || 29&nbsp;''(+1)''<br />29&nbsp;''(+1)'' || 24&nbsp;''(+6)''<br />24&nbsp;''(+6)'' || 19&nbsp;''(+11)''<br />19&nbsp;''(+11)'' || 14&nbsp;''(+16)''<br />14&nbsp;''(+16)'' || 9&nbsp;''(+21)''<br />9&nbsp;''(+21)'' || 1&nbsp;''(+29)''<br />1&nbsp;''(+29)'' || style="text-align:left" | no 
|-
|}

=== Machine guns ===
<!--''Offensive and anti-aircraft machine guns not only allow you to fight some aircraft but also are effective against lightly armoured vehicles. Evaluate machine guns and give recommendations on its use.''-->
{{main|DShK (12.7 mm)}}

{| class="wikitable" style="text-align:center"
|-
! colspan="7" | [[DShK (12.7 mm)|12.7 mm DShK]]
|-
! colspan="7" | ''Pintle mount''
|-
! colspan="4" rowspan="1" style="width:5em" |Capacity (Belt capacity)
! rowspan="1" | Fire rate <br> (shots/minute)
! rowspan="1" | Vertical <br> guidance
! rowspan="1" | Horizontal <br> guidance
|-
| colspan="4" | 250 (50) || 600 || -10°/+60° || ±180°
|-
! colspan="7" | ''Coaxial mount''
|-
! colspan="4" rowspan="1" style="width:5em" |Capacity (Belt capacity)
! rowspan="1" | Fire rate <br> (shots/minute)
! rowspan="1" | Vertical <br> guidance
! rowspan="1" | Horizontal <br> guidance
|-
| colspan="4" | 1,000 (50) || 600 || N/A || N/A
|-
|}

== 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 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). -->
The IS-4M is a direct successor to the [[IS-3]], and it features even more armour, so much armour that some APDS and APFSDS cannot penetrate its UFP and most of the turret, needless to say this tank is practically invulnerable to conventional rounds from the front. Unfortunately the gun remains the same 122&amp;nbsp;mm D-25T that is featured on all IS-series tanks from the [[IS-2]], and at Battle Rating 7.7 it isn't enough sometimes, while other times a weird bounce can be the death of the IS-4M. Overall, though, this tank feels much better at its Battle Rating than the aforementioned [[IS-3]], which has a huge shot trap.

=== General Gameplay ===
The playstyle is slightly different from its predecessor, as angling can work - it just needs to be done carefully. The frontal side armour is actually thicker than the front, so a slight angle will even-out hull armour all around (in a best case scenario it can get to 275&amp;nbsp;mm, or just slightly more). Also, the IS-4M is less mobile, because it's heavier - all speeds are dampened and mobility is heavily impaired. However, if you've played the stock [[IS-3]] this tank will feel a bit better.

'''<u>Arcade Battles</u>'''

The IS-4M will show a lot of red and yellow on the reticle when a player looks at it in Arcade. Only some HEAT and APFSDS shells can penetrate this beast frontally, and damage will only be substantial if the player takes their time to aim at the important components, because some shells will penetrate but their effect will be minimal inside the tank. However, there is little the IS-4M can do to make it harder to be damaged, because there are practically no weakspots to hide, and wiggling will not stop top rounds from penetrating.

In Arcade Battles, the improved speed should be used to rush any lone enemies and objectives. When this tank is at speed, enemies will often shoot the biggest part they see - the UFP, and many shots will bounce or not penetrate if they hit at an awkward angle; but even if they do penetrate the UFP, the IS-4M will be able to return fire because only the driver and possibly the transmission are dead. Very rarely will the IS-4M get one-shot through the UFP. Again, being at speed is being protected, and it is a big surprise to many enemies when a heavy tank drives around a corner at high speed - giving you extra seconds to take aim and disable them (usually you will pass them, so their side and/or rear is visible).

'''''Important Note:''''' Rushing mostly works in cities, where your speed is further increased by paved roads, and enemies will be spaced apart between buildings. In open areas rushing will usually end up in death, as opponents will quickly flank you because it's easy to do.

If rushing is not an option, and you find yourself in close-quarters, your best bet is to try to bait shots either for yourself or for your teammates. You can poke your gun barrel out from a corner, and if enemies shoot it, your teammates can drive out and get the kill. Poking out the side of the turret or heavily angled UFP is an option, but most enemies will realize that it's no use shooting there. 

'''<u>Realistic Battles</u>'''

In Realistic, the IS-4M retains its ability to rush, although it's subdued. When fully upgraded you can still get up to speed and surprise enemies, especially if you can choose weird routes that are not likely to be checked by enemies. From experience, it's possible to rack up 3-4 kills on city maps like Alaska, American Desert and Middle East, when playing against a good mix of lighter tanks (e.g. Leopard I, Centurion Mk 10, Vickers MBT), as well as some heavier vehicles that can be out-maneuvered.

Armour can protect the IS-4M, but most enemies usually have HEAT loaded, or will be able to load it for the next shot. Most importantly you should never find yourself fighting alone against 3 or more enemies, even 2 are hard to handle most of the time. At least when fighting one-on-one you can always try to retreat or one-shot them, depending on the situation (i.e. either gunner/gun dead or driver/transmission dead).

'''''Important Note:''''' All in all, you should play the IS-4M as if it is a slow medium tank with sub-par firepower due to the reload speed - hope that armour withstands some shots, while taking on enemies one or two at a time; if speed can be gained - use it.

=== The Stock Grind ===
The IS-4M is less painful to play when stock because at times you can get very lucky matches where no-one seems to penetrate you and you get tons of research points for withstanding a lot of shots. Nonetheless, the experience is very much similar to the IS-3 - slow tank, slow reload, gun and engine are often dead. Due to this, you must '''research Parts and FPE first''', this is extremely important. Generally, you would want to be behind your teammates, to let them get shot more instead of you, when reloaded you can poke out and shoot your shot, right before going back into the cover or behind teammates. Sniping is an option, but it's not the most viable since there's quite a lot of bullet drop and missing your shots will cause the very long reload.

=== Pros and cons ===
<!--''Summarize 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 - they have a substitution in the form of softer "inadequate", "effective".''-->

'''Pros:''' 

* Very good frontal armour; can even bounce 128 mm shells from the Maus.
* Retains the powerful D-25T 122mm gun as on the previous IS-2 and IS-3
* The mere presence of an IS-4 can make enemies panic or run and hide
* Wider choices of ammo compared to the IS-2 and IS-3.
* Good reverse speed for a heavy tank
* Can easily one-shot most tanks

'''Cons:'''

* Can - and will - be a priority target for the enemy team due to its fearsome reputation
* Long reload of 20 seconds
* Ammo rack in the back of the turret; if a shell penetrates, the ammo could detonate
* Can be vulnerable to tanks equipped with HEAT and APDSFS
* Armor penetration for the shells can be lacking at the rank

== History ==
<!--''Describe the history of the creation and combat usage of the ground vehicle in more detail than in the introduction. If the historical reference turns out to be too big, take it to a separate article, taking a link to an 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></nowiki></code>, as well as adding them at the end of the article.''-->
===Development===
During the development of the [[IS-3]] in 1944 under General Nikolai Dukhov, a separate project was underway by a design team led by L.S. Troyanov to improve the [[IS-2 (1944)|IS-2]] design. This separate project commenced under the designation ''Object 701''. The project produced three proposed design. The ''Object 701-2'' with a S-34 100 mm gun, ''701-5'' with a different armour configuration, and the ''701-6'' with the 122 mm D-25 gun. The ''701-6'' was accepted for further development, to which was modified with thicker armour, longer hull, and a more powerful engine. There was some implementation of German designs into the prototype; the engine has a cooling system that uses a pair of circular fans on the engine deck, a feature also is seen on the [[Panther A|Panther tank]].<ref name="ZalogaIS">Zaloga Steven. ''IS-2 Heavy Tank 1944-73'' Great Britain: Osprey Publishing Ltd., 1994</ref>

===Usage===
''Object 701'' was eventually approved for production in 1947 as the '''IS-4'''. The production turned out 200 tanks (some sources say 250) before the production was halted. The reason being that the IS-4 was criticized for being inadequate in mobility despite its new engine.<ref name="ZalogaIS" /> While production ended, the remaining IS-4 still saw service in the Soviet Union. When the Korean War broke out in 1950 and the United States and its allies got involved, the IS-4s were all shipped to the Far East of the Soviet Union in anticipation of Soviet intervention in the Korean War. They were not committed despite pressure by the Chinese from fear of inciting another world war. Even so, the IS-4 stayed in the region ready for action. In the late 1950s, the IS-4 underwent a modernization program along the lines of the IS-3 with increased ammo stowage, new machine gun armaments, new gun optics, better engine, and better filtration system and this modernized variant was named the '''IS-4M'''.<ref name="ZalogaIS" /> The IS-4 stayed in service in the Soviet Union until the 1960s.

===Legacy===
The IS-4, as a relatively unsuccessful Soviet tank, faded to obscurity with little information on it passed its development period. It was the heaviest of the Soviet heavy tanks that were slated for production. The IS-4's design was further developed on in the IS tank family with the ''Object 703'', with the design using an electrical transmission instead of a mechanical one. This vehicle redesignated the ''[[IS-6]]'', also proved to be problematic and was shelved.<ref name="ZalogaIS" />

=== In-game description ===
Development of this tank began in July 1943 at the ChKZ factory. The main impetus for creating a new Soviet heavy tank was the prospect of being able to install more powerful artillery on it than what was installed on the IS-2. The vehicle underwent testing until the autumn of 1944. The new vehicle had one inarguable virtue - no tank or anti-tank cannon of Soviet or German make could penetrate its 160 mm frontal armour. At the end of 1944, two more vehicles equipped with modernised transmission were produced.

In April 1945, the tank was put into service and mass-produced under the designation IS-4. The vehicle's hull was fully welded, while its turret was cast with tapering armour thickness. Along with its 122 mm D-25T cannon, it was also armed with a coaxial 12.7 mm machine gun. An identical machine gun was placed as an anti-aircraft gun on a ring mount above the loader's hatch. One of the vehicle's characteristic features was its original ammunition rack, in which shells were housed in special metal canisters. The tank had epicyclic transmission and individual torsion-bar suspension. The crew consisted of 4 people. The vehicle's powertrain was a 750 hp B-12 diesel engine. With this engine, the tank could reach 43 km/h on-road.

The IS-4 was mass-produced until 1949. In total, around 250 of them were made. These vehicles served in the Far East.

It became clear during its deployment that the tank's mass exceeded the carrying capacity of most bridges and transport platforms. It was this fact that effectively buried the idea of building vehicles with a mass greater than 50 tonnes. The IS-4 was taken out of operation and placed in long-term storage, and then withdrawn from service entirely. After this, it was often used on ballistic ranges as a target.

== Media ==
<!--''An excellent addition to the article will be video guides, as well as screenshots from the game and photos.''-->
[http://live.warthunder.com/feed/camouflages/?q=%23is4 Camouflages and skins for the IS-4 from live.warthunder.com]

==References==
<references />

== 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.''

== External links ==
''Paste links to sources and external resources, such as:''

* ''topic on the official game forum;''
* ''encyclopedia page on tank;''
* ''other literature.''

{{USSR heavy tanks}}