3-inch Mk.34 (76 mm)

3-inch Mk.34 (76 mm) on USS Mitscher

Description

The 3-inch/50 calibre Mark 34 gun was developed by the US Navy during World War II as a response to the ineffectiveness of existing 20 mm and 40 mm anti-aircraft batteries against Japanese Kamikaze attacks. Designed as an upgrade of the 3"/50 calibre Mk. 22 gun, the Mk. 34 featured an autoloader that significantly improved its rate of fire, making it more effective against fast-moving aircraft. The gun entered service too late for use in World War Two, but it saw service from the late 1940s to the 1980s, replacing 40 mm Bofors on many US and allied ships. The Mark 34 was the single-mount variant, used notably on ships like USS Roanoke and other early post-WW2 vessels.

In-game, 3-inch Mk.34 (76 mm) is an exceptionally effective anti-aircraft gun, owing to her rapid-fire HE-VT rounds and a very good vertical guidance of +85°. She can also be used against surface targets with either HE or AP rounds, though the armour-piercing ammunition suffers from a very small explosive filler.

Vehicles equipped with this weapon

• Akebono
• USS Asheville
• USS Dealey
• USS Douglas
• USS Mitscher
• USS Roanoke

General info

Being a rapid-fire gun with an excellent choice of ammunition and good penetration characteristics, the 3-inch Mk. 34 can be used in a wide variety of roles. From dealing with aerial targets to countering coastal vessels and even breaching the ammo racks of destroyers, the gun performs well in every role. Its only downside is its relatively small calibre, which limits its damage potential against larger surface targets.

Available ammunition

Penetration statistics
Ammunition	Type of warhead	Penetration @ 0° Angle of Attack (mm)
		100 m	1,000 m	2,000 m	3,000 m	4,000 m	5,000 m
HC Mk.27	HE	8	8	8	8	8	8
APHE	APHE	121	98	77	61	49	39

Shell details
Ammunition	Type of warhead	Velocity (m/s)	Projectile mass (kg)	Fuse delay (s)	Fuse sensitivity (mm)	Explosive mass (TNT equivalent) (g)	Ricochet
							0%	50%	100%
HC Mk.27	HE	823	5.9	0	0.1	500	79°	80°	81°
APHE	APHE	823	5.9	0.01	4	63.7	47°	60°	65°

Proximity-fused shell details
Ammunition	Type of warhead	Velocity (m/s)	Projectile mass (kg)	Fuse delay (m)	Fuse sensitivity (mm)	Arming distance (m)	Trigger radius (m)	Explosive mass (TNT equivalent) (g)	Ricochet
									0%	50%	100%
AA Mk.31	HE-VT	823	5.85	0	0.1	548	15	352.8	79°	80°	81°

Comparison with analogues

Typically, for post-WW2 guns, the 3-inch Mk. 34 features an excellent rate of fire and damage output. The only problematic round is the APHE, which has an unusually low explosive filler without any increase in penetration compared to guns such as the 76 mm 39-K.

HE

Cannon		Sample Ship	Ammo	Calibre (mm)	Muzzle velocity (m/s)	Sustained rate of fire (rounds/min)	Targeting speed (°/s)		Vertical guidance (°)	TNT equivalent (kg)	TNT equivalent per minute (kg)	Penetration @ 0° Angle of Attack (mm)
							Horizontal	Vertical
	3-inch Mark 10	USS Raleigh	HE	76	825	17	8.5	15	85	0.5	8.5	8
	3 inch Mk.33	Geniere	HE	76.2	823	6	20	26	85	0.5	3	8
	3-inch Mk.34	USS Asheville	HE	76.2	823	49.8	20	26	85	0.5	24.9	8
	34-K (76 mm)	Soobrazitelny	HE	76.2	845	27	12	8	85	0.483	13.04	8
	39-K (76 mm)	Tashkent	HE	76.2	845	20	18	11	87	0.483	9.66	8
	76 mm/60 AK-176M	MPK Pr.12412	HE	76.2	845	20	30	26	85	0.616	12.32	10
	AK-726 (76 mm)	SKR-7	HE	76.2	980	16.2	26	30	85	0.616	9.98	10
	3 inch 12pdr 12 cwt QF Mk.V (76 mm)	HMS Churchill	HE	76.2	823	17	25	25	70	0.5	8.5	8
	76 mm/45 QF 3in 20cwt (76 mm)	HMS Valhalla	HE	76.2	762	12	13	10	40	0.32	3.84	6
	Type 88 AA (75 mm)	Type 5	HE	75	720	20	21	20	50	0.42	8.4	5
	8 cm/40 3rd Year Type (76 mm)	Type K-8 No.13 late	HE	76.2	685	20	11	10	75	0.48	9.6	8
	8 cm/60 Type 98 (76 mm)	IJN Agano	HE	76.2	902	25	18	16	85	0.399	9.98	7
	76 mm/40 Ansaldo mod.1917 (76 mm)	RN Aquila	HE	76.2	690	15	11	10	75	0.65	9.75	10
	76 mm/62 OTO-Melara Compact (76 mm)	Sparviero	HE	76	925	85.7	51	30	85	1.08	92.57	15
	76 mm/62 SMP 3 (76 mm)	Albatros	HE	76.2	930	8.57	34	60	85	0.864	7.40	15
	75 mm/50 model 1922	Duguay-Trouin	HE	75	850	15	19	18	85	0.45	6.75	8

SAP/AP

Cannon		Sample Ship	Ammo	Calibre (mm)	Muzzle velocity (m/s)	Sustained rate of fire (rounds/min)	Targeting speed (°/s)		Vertical guidance (°)	TNT equivalent (kg)	TNT equivalent per minute (kg)	Penetration @ 0° Angle of Attack @ 5000 m (mm)
							Horizontal	Vertical
	3-inch Mark 10	USS Raleigh	APCBC	76	823	17	8.5	15	85	0.13328	2.27	57
	3-inch Mk.34	USS Asheville	APHE	76.2	823	49.8	20	26	85	0.0637	3.17	62
	34-K (76 mm)	Soobrazitelny	APHEBC	76.2	816	27	12	8	85	0.119	3.21	65
	39-K (76 mm)	Tashkent	APHEBC	76.2	816	20	18	11	87	0.119	2.38	65
	Type 88 AA (75 mm)	Type 5	APHEBC	75	720	20	21	20	50	0.150	3	55
	76 mm/40 Ansaldo mod.1917 (76 mm)	RN Aquila	APHE	76.2	690	15	11	10	75	0.319	4.79	20
	76 mm/62 OTO-Melara Compact (76 mm)	Sparviero	SAP	76	925	85.7	51	30	85	0.6552	57.46	32

Usage in battles

The 3-inch Mk. 34 is usually assigned to either the secondary or primary armament group. Vessels that have it in the secondary group will automatically engage enemy aircraft and surface combatants using AI gunners, but manual control can be taken over with the use of select secondary weapon control (default Alt+2). If the gun is in the primary group, it can be delegated to AI by switching to any other weapon group (weapon group switch, default Left Ctrl+E). This is important, as AI gunners will engage enemy vessels from as far as 4 kilometres away, which, combined with the HE-VT rounds, can often be a lifesaver, destroying enemy aircraft long before they have an opportunity to drop bombs on your vessel.

The gun is also very effective against surface vessels, particularly motor torpedo boats, owing to her high rate of fire and good muzzle velocity, making it easy to correct aim on target, while the HE rounds will effectively destroy them in a few hits. Against frigates and destroyers, a choice of APHE rounds might be preferable, especially when targeting ammo racks.

Pros and cons

Pros:

• High rate of fire
• Excellent vertical guidance
• Often available in a twin-mount
• Good muzzle velocity
• Access to a wide choice of rounds

Cons:

• Very low explosive filler of the APHE rounds, equivalent to only 63.7 grams TNT

History

The 3-inch Mk. 34 gun was developed by the United States Navy in response to Japanese Kamikaze attacks. Designed as an intermediate-calibre solution between the lighter 40 mm Bofors and the heavier 5-inch/38 (127 mm), the gun used a 76.2 mm, 50-calibre-long barrel with an electrically-driven autoloader. This allowed for a high rate of fire and tracking of fast-moving aircraft.

The Mk. 34's single mount was similar in size to the quad 40 mm Bofors, and despite the heavier mass, it was possible to replace Bofors on a one-for-three basis. During the testing, it was found that a single 3"/50 was as effective as two 40 mm quad guns.

The initial prototype was ready by 1 September 1945, but with the end of the war, deployment was delayed until 1948. It became the weapon of choice on numerous US and allied ships from the late 1940s through to the 1980s. However, the history of the gun dates back to 1915, when the initial versions were introduced as dual-purpose weapons, undergoing modernisations and redesigns over the decades, culminating in the Mk. 34, which was the last significant upgrade for the gun.

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 article about the variant of the cannon/machine gun;
• references to approximate analogues by other nations and research trees.

External links

• [Wikipedia] 3-inch/50-caliber gun
• [NavWeaps] 3"/50 (7.62 cm) Marks 27, 33 and 34

Japan naval cannons
20 mm	JM61 · Type 98
25 mm	25 mm/60 Type 96
37 mm	Type 4 · Type 11 pattern 1922
40 mm	40 mm/62 Vickers
57 mm	Type 97
75 mm	Type 88 AA
76 mm	3-inch/40 Type 41 · 8 cm/40 3rd Year Type · 8 cm/60 Type 98
100 mm	100/65 mm Type 98 mod A
120 mm	120 mm/45 3rd Year Type · 120 mm/45 10th year type
127 mm	5 inch/40 Type 89 · 127 mm/50 3rd Year Type
140 mm	140 mm/50 3rd Year Type
152 mm	6-inch/45 Type 41 · 15 cm/50 Type 41
155 mm	155 mm/60 3rd Year Type
200 mm	20 cm 3rd year type No.1
203 mm	20 cm/45 Type 41 · 20 cm/50 3rd year type No.2
356 mm	36 cm/45 Type 41
410 mm	410 mm/45 Type 3
	Foreign:
20 mm	20 mm/70 Oerlikon Mk.II (USA/Britain)
40 mm	Bofors L/60 Mark 1 (USA) · Bofors L/60 Mark 2 (USA) · Bofors L/60 Mark 3 (USA)
47 mm	3 pdr QF Hotchkiss (Britain)
76 mm	3-inch Mark 10 (USA) · 3 inch Mk.33 (USA) · 3-inch Mk.34 (USA)
120 mm	4,7-inch/40 Armstrong (Britain)
127 mm	5 inch/38 Mk.12 (USA)
305 mm	12-inch/45 Vickers (Britain) · 12-inch/50 Vickers (Britain)