From War Thunder Wiki
Jump to: navigation, search
120 mm Gun Tank M103
General characteristics
5 peopleCrew
214 %Visibility
front / side / backArmour
127 / 51 / 38Hull
162 / 159 / 58Turret
56.7 tWeight
1 545 hp810 hpEngine power
27 hp/t14 hp/tPower-to-weight ratio
35 km/h forward
8 km/h back
33 km/h forward
8 km/h back
33 roundsAmmunition
14.9 / 19.4 sReload
-8° / 15°Vertical guidance
12.7 mm M2HB machine gunMachinegun
1 000 roundsAmmunition
8.0 / 10.4 sReload
200 roundsBelt capacity
577 shots/minFire rate
-10° / 45°Vertical guidance
-60° / 60°Horizontal guidance
2 x 7.62 mm M1919A4 machine gunCoaxial weapon
8 000 roundsAmmunition
8.0 / 10.4 sReload
250 roundsBelt capacity
500 shots/minFire rate
170 000 Rp icon.pngResearch
440 000 Sl icon.pngPurchase
Sl icon.png6 050 / 8 185/5 350 / 7 238/4 840 / 6 548Repair
130 000 Sl icon.pngCrew training
440 000 Sl icon.pngExperts
1 400 Ge icon.pngAces
208 % Rp icon.pngReward for battle
180 % Sl icon.png150 % Sl icon.png140 % Sl icon.png


GarageImage M103.jpg

The 120 mm Gun Tank M103 is a rank V American heavy tank with a battle rating of 7.7 (AB/RB/SB). It is one of the first American tanks to be released with the American ground tree in Update 1.45 "Steel Generals".

General info

Survivability and armour

Armour type:

  • Cast homogeneous armour
  • Rolled homogeneous armour (Turret roof)
Armour Front (Slope angle) Sides Rear Roof
Hull 114.3 mm (55-66°) 50.8 mm Upper
44.44 mm Lower
38 mm 25.4 mm
Turret 127 - 350 mm 76.2 - 93 mm 51 mm 38 mm


  • Suspension wheels are 20 mm thick and tracks are 30 mm thick.
  • Hull armour: After the fantastic T32, the M103's armour situation is generally a letdown. Its side armour is nearly nonexistent, same applying to the rear. The M103's turret size was also increased while reducing the armour down from 152mm to ~85mm average. But all hope is not lost - the M103's armour design did improve. Unlike its predecessor, it features slopes and angles everywhere, making the M103 a difficult target to destroy from the front. It is also reassuring to know that the frontal chassis is no longer a big weak spot; it is relatively minor and can reliably bounce shots right into the armoured gun mantlet.
  • Turret armour: The M103's turret fares better. It is designed to take on tanks from the front, as the line of sight thickness exceeds 300mm on many occasions and where it doesn't the angle will result in bounces. However, this only works when facing straight at the enemy. Any slight angling miscalculation and the Line of Sight armour becomes useless.
  • Weak spots: The worst part of the M103 is its true weak spots. As mentioned previously, the upper glacis and lower gun mantlet tend to bounce shots into each other, often with deadly results. Furthermore, the bottom turret cheeks are not as well angled as the rest of the turret (~176mm) and can even be penetrated by the long 88 mm KwK 43. The biggest issue present is the abnormally large turret ring. It is visible all around the tank, and with merely 127 mm of armour it attracts many shots. This, in combination with the "shot trap", presents a very deadly scenario: Either the enemy hits the turret ring and incapacitates the entire crew with one APHE shell, or the shell strikes the mantlet/glacis and still does massive damage to either the driver's compartment or the gun breech. Keep the turret ring hidden! Another small weakness is that the M103's belly armour is only 38.1 mm thick, meaning most high-explosive rounds used by the Rank V tanks, HESH, can be splashed under the M103 and actually penetrate it with the explosion alone.


Game Mode Max Speed (km/h) Weight (tons) Engine power (horsepower) Power-to-weight ratio (hp/ton)
Forward Reverse Stock Upgraded Stock Upgraded
Arcade 35 8 56.7 1046 1,545 18.45 27.25
Realistic 33 8 716 810 12.63 14.29


Main armament

Main article: M58 (120 mm)
120 mm M58 Turret rotation speed (°/s) Reloading rate (seconds)
Mode Capacity Vertical Horizontal Stabilizer Stock Upgraded Full Expert Aced Stock Full Expert Aced
Arcade 33 -8°/+15° ±180° NA 19.42 26.88 32.60 36.10 38.40 19.37 17.14 15.79 14.90
Realistic 14.28 16.80 20.4 22.60 24.00
Penetration statistics
Ammunition Type of
Penetration in mm @ 0° Angle of Attack
10m 100m 500m 1000m 1500m 2000m
M358 shot AP 300 298 286 272 258 245
M356 shell HE 45 45 44 43 43 43
M469 shell HEATFS 380 380 380 380 380 380
Shell details
Ammunition Type of
in m/s
Mass in kg
Fuse delay

in m:

Fuse sensitivity

in mm:

Explosive Mass in g
(TNT equivalent):
Normalization At 30°
from horizontal:
0% 50% 100%
M358 shot AP 1,067 23.1 N/A N/A N/A -1° 48° 63° 71°
M356 shell HE 762 22.8 0.1 0.1 4,650 +0° 79° 80° 81°
M469 shell HEATFS 1,143 23.8 0.0 0.1 2,670 +0° 65° 72° 75°
Smoke characteristic
Ammunition Velocity
in m/s
Mass in kg
Screen radius
in m
Screen time
in s
Screen hold time
in s:
Explosive Mass in g
(TNT equivalent):
M357 762 23 20 5 25 50
Ammo racks
Ammo racks of the M103.
rack empty
rack empty
rack empty
rack empty
33 Projectiles
12 (+21)
24 (+9)
14 (+19)
10 (+23)

Machine guns

12.7 mm M2HB
Pintle mount
Capacity (Belt capacity) Fire rate
1,000 (200) 576 -10°/+70° ±60°
7.62 mm M1919A4
Coaxial mount (#1)
Capacity (Belt capacity) Fire rate
4,000 (250) 500 N/A N/A
Coaxial mount (#2)
Capacity (Belt capacity) Fire rate
4,000 (250) 500 N/A N/A

Usage in battles

Armed with an extremely large 120 mm cannon, the tank boasts superior firepower rivalling many other Rank V vehicles. One thing must be said from the start: The full name of the M103 is "120 mm Gun Tank M103" and not "Heavy tank T32". As the title already hinted, this tank is all about the cannon, a Gun tank. This defines the general play style of the tank in both arcade and realistic mode: it is a sniper with the sole role of making the enemy's life as miserable and short-lived as possible. The cannon can compete against the armour of the Maus!

One thing to note is that the M103's play style is very different from its predecessor T32. Aside from the increase in firepower with the 120 mm cannon, the armour on the M103 is actually slightly weaker than the T32. The M103's gun mantlet is still good with ~300 mm line of sight thickness, but any other spot on the tank is weaker. The tank's upper glacis is, however, a major improvement and mostly a ricochet zone. If impacted, the shells usually travel straight into the turret or gun. Against later Soviet and German tanks, the front of the M103 is vulnerable. Even by using the "hull down" tactic as with the T32, the tank can still be penetrated. However, half-turret down will net better results. The sides, as on most US tanks, are still very thin and vulnerable with no major changes from previous models.

However, the armour of the M103 is not all bad; while it is not thick, the way it angles will deflect many shots. A badly placed shot will easily ricochet, or be swallowed by the line of sight thickness. A head-on engagement is the M103's greatest strength as its frontal armour performs similarly to the IS-3's frontal pike nose. Due to the shape of the hull, it being boat-like, you may bounce some low caliber shells off the lower side of your hull.

With range, the advantages of the M103 increase while its disadvantages recede. It is, therefore, the perfect tank for large, open maps like Mozdok and Kursk, where flanking tanks can easily be spotted and dealt with


The M103 is best played at medium to long range, making use of its 120 mm cannon to devastate enemies at a long distance. The vehicle's armour is more about slope than actual thickness, so the long distance also helps to mitigate the M103's rather large armour gaps. The tank also has good gun depression, so making use of hills is advised wherever possible. If on a city map, and have no long-range opportunities, stay close to teammates and move up only as warranted. The 120 mm has a fairly long reload, and in close quarters, can get the M103 destroyed during the downtime. As such, keep a back-up plan an escape route handy, as a missed, bounced, or non-lethal shot can leave the M103 exposed to enemy return fire.

The M103 also comes with a smoke round in case it's needed, but unless it's used to cover a pre-engagement advance, it's best to keep it in reserve only. The long reload of the gun can make loading a smoke round a fatal error, should the M103 get caught mid-reload, or worse, have to cease a reload halfway through to load a more suitable round.


Tier Mobility Protection Firepower
I Tracks Parts Horizontal Drive
II Suspension Brake System FPE Adjustment of Fire M469 shot
III Filters Crew Replenishment Elevation Mechanism NVD
IV Transmission Engine M357 Rangefinder

It comes without question that this tank, whose sole defining aspect is its gun, should rely first on parts to keep the barrel smoking. For the second upgrade, which also unlocks other tier two upgrades, "Turret Drive" is recommended. The M103 has no mobility problems and therefore tracks can generally be neglected. However, its second tier unlocks are very useful. "FPE" is beneficial against the fires caused by the engine, but the 380 mm penetration HEAT shells and "Adjustment of Fire" for better accuracy are nothing to ignore. When choosing upgrades, ask this question: Is the normal APBC shot enough? Would I have benefited from being able to put out a fire? Does better accuracy help me to get more targets? Choose wisely! After all these three modules are researched, there is not a lot left. "Elevation Mechanism" is always nice, same for "Engine" and "Transmission".

Pros and cons


  • Has one of the largest calibre guns in the game that fire solid AP shots
  • Excels in long-range combat on open maps
  • Decent gun depression of -8 degrees for hull-down positions
  • The M358 AP round is one of the strongest rounds available
  • Great post-penetration for AP
  • Very fast turret traverse rate
  • Frontal armour is very strong against all but the most well-aimed and large calibre shots
  • Sloped front glacis can deflect most AP shots
  • Quite mobile for a heavy tank, even with stock modifications
  • Reaches max speed (33 km/h) even when stock and going off-road
  • .50 cal machine gun can provide some AA defence
  • Stock AP rounds can one-shot almost anything - pending good shot placements
  • Has a rangefinder


  • HEATFS has relatively low penetration compared to contemporary enemy tanks
  • Tank can only hold 33 rounds
  • Rather long reload of more than 15 seconds
  • Turret shot trap present and could be shot at
  • Turret ring is vulnerable
  • Belly armour is only 38.1 mm thick
  • Not close-engagement friendly
  • Sides and rear of turret and hull are very weak, less than 50.8 mm thick
  • In up-tiers, where shell penetration quickly outpaces armor improvements, the armor on the M103 is more of a curse than a benefit as it slows the tank down and rarely stops shells.



The M103 tank was designed to counter the Soviet heavy tanks being produced at the time, namely the IS-3 and the T-10M heavy tanks, which prove rather impervious to Western tank designs such as the M26 Pershing and Centurion. The problem facing the designers at the time was to produce a versatile tank system capable of engaging heavy tanks like the IS-3 and fortifications.

The result of the request for such of a vehicle was the experimental T34 heavy tank, which was a variant of the then-experimental T29 Heavy tank except mounting the much larger 120 mm T53 cannon rather than a 105 mm T5E2 cannon. Further development began on this tank in 1948, where multiple changes were made to the design to fit a more versatile tank system. The end result was the now named T43 Heavy Tank, which began to see the doubt in its success as the Korean War was undergoing at the time that placed the M26 Pershing back in the spotlight. The T43 managed to survive due to an order request of 80 units by the Army to reinforce their depleted armoured forces. The USMC even sought a replacement that could serve for a long period of time and ordered 220 of the vehicle in 1951. Changes were made to the armour protection and the gun was updated to the newer 120 mm T123E1 cannon. After being sent to Aberdeen Proving Ground and approved, it was accepted under the T43E1 designation.

The 120 mm T123E1 cannon (adopted as the M58 gun) was a very large cannon, and the ammo could penetrate about 340 mm of armour up to 1,000 yards. However, the ammo's large size restricted the number that could be held in the tank turret and hull. The design also had a 7.62 mm machine gun and a .50 cal machine gun could be installed on the turret to provide anti-aircraft and anti-personnel fire. The heavy weight of the design at 59 tons caused the Continental AV1790 engine to be insufficient in propelling the tank. Thus, the tank's speed was only about 34 km/h (21 mph). Despite the weight, it was still 10 tons lighter than its predecessors and retained about the same armour protection ratings. The production of the T43E1 tank was designated as the M103 tank and was produced at Chrysler Newark for a total of 300 units produced.


The M103 was fielded in Europe in only one battalion in January 1958. The 889th Tank Battalion (later as the 2nd Battalion, 33rd Armor Regiment) was organized to four companies of six platoons each. Each platoon had three M103 heavy tanks for eighteen tanks per company. The United States Marine Corps had one M103 company of about seventeen tanks assigned to each of its three Marine tank battalions in regulars and reserves.

The M103 never saw combat during its service life from 1957 to 1974 and the US Heavy Tank Battalions began to be deactivated around 1963 with the arrival of the M60 Main Battle Tank, which proved to be much better in the long terms compared to the M103. The Marines kept their M103s until they began receiving the M60 tanks to replace them. The removal of the heavy tank units in the US military was the time of turnover from the traditional classification of weight between a tank to the new concept of "main battle tanks" and "airborne vehicles". These ushers in the new age of main battle tanks that can serve in a multi-purpose role against armour and fortifications, starting in the M60 tank, then in its successor the M1 Abrams. The M1 Abrams, while having the same calibre as the M103, was much more powerful due to its new ammunition types and design, and was a statement on the advancement of technology that came in about thirty years difference between the two tank designs.

Today, only a few M103 samples are left intact around America in various bases and museums.

In-game description

"By the end of the Second World War the M26 Pershing was the primary heavy tank for the American armed forces, though it was later redesignated a medium tank. The US at the same time was working on new heavy tanks, creating the T29, T30, T34, and T32 prototypes.

Having released the first T43 pilot model for testing in the summer of 1951, the Detroit Tank Arsenal (Chrysler) introduced a large number of changes to the project. The three subsequent pilot models were designated T43E1s, and worth noting among the significant changes made was the new 120 mm M58 (T123) cannon. New barrel production technology boosted pressure in the chamber as well as initial velocity. The M103's hull and turret were built as intricate, bulky molded pieces with flat welded armor plates on the bottom. The traditional design featured the power unit and transmission in the rear.

After testing began in 1953 for the pilot and production models, 98 changes were made to the design. In April 1956 the tank was standardized and sent to production as the 120 mm Gun Full-Tracked Combat Tank M103. In all, 74 of the first 80 T43E1 tanks were updated to meet M103 standards.

Operations in Europe uncovered yet another list of problems plaguing the tank: difficult working conditions for the crew, an underpowered engine that overworked both it and the transmission, a barrel that quickly showed wear when frequently firing armor-piercing rounds, and much more.

The Marine Corps later ordered a final modernization for the tank: after the basic M60 was accepted, its diesel engine and fire control system were adapted. The new model was designated the M103A2."




See also

  • Conqueror Mk 2 - British counterpart of the heavy tanks, using the same gun design.

External links

USA heavy tanks
M4 Jumbo  M4A3E2 · Cobra King · M4A3E2 (76) W
Small-scale series  T14 · M6A1 · T26E1-1
Post-war  T29 · T30 · T32 · T32E1 · T34 · M103