Catalina Mk IIIa (Great Britain)

M50

M56

T95

M50

M56

T95

USA

IV Rank

Battle rating:

AB	RB	SB
6.7	6.7	6.7

Class:

Tank destroyer

Research:63 000

Purchase:200 000

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Description

The Rifle, Multiple, 106-mm, Self-Propelled, M50, also known by the nickname Ontos, is a rank IV American tank destroyer with a battle rating of 6.7 (AB/RB/SB). It was introduced in Update 1.71 "New E.R.A".

The M50 "Ontos" is pretty much a bulky carrier of recoilless rifles, carrying a payload of six shells of devastating HEAT and HESH shells. With six launchers pointing forwards, a well-emplaced M50 can point itself downrange and once a target comes into its sights, unleash all shells until the target is annihilated.

A stealthy and pouncing game style is needed to make the most of the hard-hitting guns and the thin armour of the Ontos.

General info

Survivability and armour

Armour	Front (Slope angle)	Sides	Rear	Roof
Hull	10-13 (70°) Front glacis 13 mm (45-66°) Lower glacis	13 mm (43°) Top 13 mm Bottom	13 mm (36°) Top 13 mm Bottom	13 mm
Armour	Sides	Roof
Cupola	13 mm	13 mm

Notes:

• Suspension wheels and torsion bars are 20 mm thick while tracks are 15 mm thick.

Mobility

Game Mode	Max Speed (km/h)		Weight (tons)	Engine power (horsepower)		Power-to-weight ratio (hp/ton)
	Forward	Reverse		Stock	Upgraded	Stock	Upgraded
Arcade	53	18	8.3	206	277	24.82	33.37
Realistic	49	17		128	145	15.42	17.47

Armaments

Main armament

106 mm M40A1C
Capacity (Belt capacity)			Vertical guidance	Horizontal guidance	Stabilizer
18 (6)			-10°/+20°	±40°	N/A
Turret rotation speed (°/s)
Mode	Stock	Upgraded	Prior + Full crew	Prior + Expert qualif.	Prior + Ace qualif.
Arcade	15.9	21.9	__.__	__.__	__.__
Realistic	10.7	12.6	15.3	16.9	18.0
Reloading rate (seconds)
Stock	Prior + Full crew	Prior + Expert qualif.	Prior + Ace qualif.
16.90	14.95	13.78	13.00

Ammunition

Penetration statistics
Ammunition	Type of warhead	Penetration in mm @ 90°
		10m	100m	500m	1000m	1500m	2000m
M344A1	HEAT	381	381	381	381	381	381
M361A1	HESH	152	152	152	152	152	152

Shell details
Ammunition	Type of warhead	Velocity in m/s	Projectile Mass in kg	Fuse delay in m:	Fuse sensitivity in mm:	Explosive Mass in g (TNT equivalent):	Normalization At 30° from horizontal:	Ricochet:
								0%	50%	100%
M344A1	HEAT	502	10	0.0	0.1	1,650	+0°	62°	69°	73°
M361A1	HESH	498	10	0.4	0.1	5,040	+0°	73°	77°	80°

Ammo racks

Ammo racks of the M50.

Full ammo	1st rack empty	2nd rack empty	Visual discrepancy
18	10 (+8)	0 (+18)	No

Six shells are loaded per reload.

Machine guns

12.7 mm M8C
Coaxial mount (x4)
Capacity (Belt capacity each)				Fire rate (shots/minute)	Vertical guidance	Horizontal guidance
480 (4)				300	N/A	N/A

7.62 mm M1919A4
Pintle mount
Capacity (Belt capacity)				Fire rate (shots/minute)	Vertical guidance	Horizontal guidance
1,000 (250)				500	-5°/+50°	±70°

Usage in battles

M50 Ontos at the National Museum of the Marine Corps

Obviously the M50 is not a main battle tank, with its thin armour even Reserve units are a threat! Stealth and guile is the tactic, using its high mobility and small size to get in ambush or outflank an enemy push fast. Memorize shooting spots, be it concealed ambush points or sheltered ranged locations overlooking active routes. The most important tactic is learn how to operate it! Keymap a separate trigger for the spotting gun and learn the firing sequence! Nothing worse than sight a perfect target, but the gun on the wrong side is fired into a rock! Also keep in mind the turret has only 80 degrees of traverse (+/- 40), a consideration during tactical maneuvers. Still, compared to other ATG's this traverse is much wider, and also has a respectable -10 depression. Add that -10 degrees and angled position to the already extremely sloped front glacis armor and one could be bouncing large caliber AP rounds! Don't forgot to spot enemies too, make them feel the pressure, not you.

Modules

Tier	Mobility		Protection	Firepower
I	Tracks		Parts	Horizontal Drive
II	Suspension	Brake System	FPE	Adjustment of Fire	Airstrike
III	Filters		Crew Replenishment	Elevation Mechanism
IV	Transmission	Engine		Improved optics

Pros and cons

Pros:

• Six recoilless 106 mm rifles
• The guns can be fired within 0.5 seconds of each other, allowing rapid fire on one helpless target
• Stock shells of HEAT and HESH
• The HEAT shell is really effective, literally point and shoot
• Four heavy machine guns coaxial to guns - Can be used for spotting
• 33 mph/53 kph nice speed, can get to ambush or sniping positions early game or rush capture point
• Spotting Gun allow you to instantly adjust aim, improve accuracy.

Cons:

• No armour whatsoever (can be easily destroyed by heavy MG rounds or via air strafing)
• Only 18 rounds - can't miss and be wasteful
• Only 2 crew members - One shot is most likely to put you out of action
• Spotting machine guns are hard to utilize, firing only in unison with the guns as default or separately with key bindings
• Pintle mounted machine gun is quite ineffective against even aircraft found at this rank
• Use of Spotting Gun and main gun needs practice to be proficient and successful.

History

It was such a strange “tank” the only word the US Army could think of for this strange thing was, well, “Thing”, except someone was clever and used the Greek word, ὄντος (really, truly [exists]).  Due mountainous and difficult terrain of Korea brought the US Army revisited the idea of a light tank.  It was quite an ingenious design made very quickly.  The prototype was based on an M56 Scorpion ATG chassis, used a common truck engine, and mounted six very powerful M40A1C recoilless rifle guns and be light enough for air transport.  The prototype was finished in 1952 and by 1955 completed its testing where it fulfilled its design requirements, but the Army simply did not like this monstrosity and decided against it.  The US Marines on the other hand was not as picky and loved this highly mobile light tank with a huge punch, so ordered 297 in 1955.  The design was reworked with a new chassis, new running gear with wide thread (ditching the M56 design), better internal layout, and other minor improvements that made the Ontos a unique one off design.   While it had a few flaws, it was reliable enough to accomplish its mission.

The key to the M50’s offensive power is the 106mm M40A1C recoilless rifle firing devastating HEAT or HESH rounds with its integrated M8C .50 cal spotting rifle using a 10 or 20 round magazine. It should be noted the M8C is a shorter round (12.7x77mm, M48A2 Spotter-Tracer (S) bullets only) that the better known .50 AN/M2 BMG (12.7x99mm).  Every M40 produced had the M8C, but on the M50 the lowest 2 barrels have this spotting rifle removed leaving an empty mounting post.   If wanted (but not recommended) all 6 guns can be fired at once delivering far more destructive offensive load than any tank then or today.  The nature recoilless rifles is a powerful blow back, during a test firing all 6 it knocked bricks out of a building and shatters a few car windows.  At the top mounted a single .30 caliber M1919A4 machine gun for anti-infantry use.

The first combat use of the Ontos occurred in 1964 Dominican Republic  Civil War where it reported destroyed an AMX-13 and an old Swedish L-60 (the only time it was used for purpose built, destroy tanks). But it was the following year when it was deployed to Vietnam . 

Vietnam was extremely hostile to tanks, not due to enemies but the environment.  Jungle, swamp, rice fields, mountains, rivers, a limited road network with small bridges; it was a nightmare for regular tanks but the Ontos could glide over them with ease.  Enemy Vietnamese troops rarely used tanks and few anti-tank guns so there was little threat from them, the paper thin armor was more than enough to resist small arms and heavy MG fire.  The significant vulnerability of reloading the 6 guns was largely moot as the fearsome reputation of this 6 shooter beast often cleared out enemy positions soon after it started shooting.  Unfortunately its age was its greatest enemy.  Over 10 years old and long out of production breakdowns became more frequent, some were cannibalized for parts and the turrets where mounted to fixed positions as point defense.  Despite its unprecedented success in Vietnam its limited numbers, scattered deployment, breakdowns, and frequent rotation it did not gain as much fame as it could have. More of footnote today, this unusual tank was the perfect vehicle for very difficult conflict.

Media

Excellent additions to the article would be video guides, screenshots from the game, and photos.

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

• [Devblog] M50 Ontos - Something Out of The Ordinary

USA tank destroyers
M10	M10 GMC
M36	M36 GMC · M36B2
T95	T28 · T95
M109	M109A1
ATGM	LOSAT · M901 · ADATS
Wheeled	M3 GMC · T55E1
Other	M8 HMC · M50 · M56
China	▃LVT(A)(4) (ZIS-2)