Type 99 Model 2 (20 mm)

This page is about the Japanese cannon Type 99 Model 2 (20 mm). For the other version, see Type 99 Model 1 (20 mm). For other uses, see Type 99 (Disambiguation).

Description

The 20 mm Type 99 Model 2 was the main aircraft cannon for the Imperial Japanese Navy during WW2, replacing the earlier drum-fed Type 99 Model 1. It was mounted on nigh every IJN aircraft in a pair or quad setup, allowing for a significant firepower boost that helped the fighters of the time compete with the exceedingly well-armed American aircraft that they faced.

The principal differences between Model 2 and Model 1 consist of a longer barrel, longer chamber, and longer cartridge to boot. The barrel protrudes 18 inches beyond the leading edge when mounted in the wings of fighter aircraft. The projectiles used are identical to the Model 1, but the cartridge employed contains approximately 40% more propellant than the older type, thereby increasing the velocity of the Model 2 to a respectable 750 m/s as opposed to the Model 1's 600 m/s.

While all Type 99s are labeled as simply Type 99 Model 1 and Type 99 Model 2 (with the exception of Type 99 Model 2 Mark 5), there are variants between them that mainly only reflect in ammo count:

• Type 99 Model 2, Mark 3 - (100 rds Drum) Base model 2 has a longer barrel over the Type 99 Model 1, Mark 3.
• Type 99 Model 2, Mark 4 - (125 - 250 Belt) Switched out to a belt-fed system.
• Type 99 Model 2, Mark 5 - (125 - 250 Belt) Increased fire-rate from ~500 RPM to ~720 RPM.

Vehicles equipped with this weapon

Vehicles equipped with this weapon
Type 99-2, Mark 3
A6M	A6M3 mod. 22Ko · A6M5
J1N	J1N1
J2M	J2M2
N1K	N1K1-Ja
Type 99-2, Mark 4
A6M	A6M5 Ko · A6M5 otsu · A6M5 Hei · A6M6c
A7M	A7M1 (NK9H) · A7M2
B7A	B7A2 · B7A2 (Homare 23)
J2M	J2M3 · J2M4 Kai · J2M5
J5N	J5N1
J6K	J6K1
N1K	N1K2-J · N1K2-Ja
Type 99-2, Mark 5
G8N	G8N1 (Defensive)

General info

Type 99 Model 2 Mark 3

The Model 2 cannons have a rate of fire of 490 RPM, for both Mark 3 and 4, while the later Model 2 Mark 5 cannon had a sustained rate of fire of 750 RPM. Muzzle velocity is average, between 700 m/s and 750 m/s depending on the shell. It is of note that the Model 2 cannons typically hold a large amount of rounds per gun, ranging from 100 to 250, which allows for a significantly large ammunition pool in its traditional quad or double mount setup.

Available ammunition

With 5 belts available to the Type 99 Model 2 which vary in role and priority

All-around

• Universal: Offering the best all-around belt with HEF-T for tracking the bullet, 2x HEF which offers the highest explosive mass off all available bullets in the Type 99 and a single AP-I every 4 bullets for armoured targets, which also offers decent incendiary damage.

Specialized

• Ground Targets: Offering 4x AP-I shells in a row, it this belt can be greatly used against soft to medium armoured targets in ground battles penetrating up to 20 mm up to 500 m which most tanks don't have in roof armour. If air targets appear, the AP-I still offers decent incendiary damage with 2x HE shells to back it up.
• Stealth: A specialized belt for the most experienced pilots, offering no tracers in return for more of the better HEF shells with 2x AP-I shells offering a slightly better armour burst compared to all other belts (excluding Ground Targets).
• Tracers: A full HEF-T that can be used to get consistent results and at all times visible due to the tracer, offering a purely anti-air belt for the newest pilots to the Type 99 Model 2. Keep in mind the HEF-T only has half the explosive mass compared to HEF.

Other

• Default: While being the stock belt, it is the weakest of them all, lacking in any degree because of the regular T shell, and 2 very lackluster FI shells. The single AP-I can cause reliable fires if landed on target but can only be used once every 4 shells.

Belts:

Offensive

• Default: T · FI · FI · APHE
• Universal: HEF-T · HEF · HEF · APHE
• Ground targets: APHE · APHE · APHE · APHE · HEF · HEF-T
• Tracers: HEF-T
• Stealth: HEF · HEF · HEF · APHE · APHE

Defensive

• Default: T · FI · APHE
• Armoured targets: APHE · APHE · APHE · HEF-T
• Air targets: HEF-T · FI · HEF-T · FI · APHE

Penetration statistics
Ammunition	Penetration @ 0° Angle of Attack (mm)
	10 m	100 m	500 m	1,000 m	1,500 m	2,000 m
FI	4	4	4	4	4	4
T	16	13	8	6	0	0
APHE	26	24	17	10	6	4
HEF-T	4	4	3	3	3	3
HEF	4	3	3	3	3	3

Shell details
Ammunition	Velocity (m/s)	Projectile mass (kg)	Fuse delay (m)	Fuse sensitivity (mm)	Explosive mass (TNT equivalent) (g)	Ricochet
						0%	50%	100%
FI	750	0.13	0.05	0.1	5	47°	56°	65°
T	750	0.13	-	-	-	47°	56°	65°
APHE	750	0.13	0	0	4.84	47°	60°	65°
HEF-T	750	0.13	0.05	0.1	8.5	79°	80°	81°
HEF	750	0.13	0.05	0.1	16.83	79°	80°	81°

Comparison with analogues

Name	Cartridge	Projectile weight (grams)	Rate of fire (rpm)	Muzzle velocity (m/s)	Gun weight (kg)
France
Hispano 404	20 × 110	130	700	880	60
Germany
MG FF	20 × 80RB	134	520	600	28
MG FF/M	20 × 80RB	92/115	540/520	700/585	28
MG 151/20	20 × 82	92/115	750–800	800/720	42
Japanese Army
Ho-1	20 × 125	144	400	805	45
Ho-3	20 × 125	144	400	805	45
Ho-5	20 × 94	96	750–850	715	37
Japanese Navy
Type 99 Mark 1 Model 2~3	20 × 72RB	129	520~550	600	23~27
Type 99 Mark 2 Model 3~5	20 × 101RB	129	480~720	750	35~38
Great Britain
Hispano Mk.II (20 mm)	20 × 110	130	600	880	50
Hispano Mk.V (20 mm)	20 × 110	130	750	840	42
USSR
ShVAK	20 × 99R	95	800	750–770	42
B-20	20 × 99R	95	800	750–770	25
VYa-23	23 × 152B	200	550	880	69
NS-23	23 × 115	200	550	690	37
United States
AN/M2	20 × 110	130	600–700	870	51
M3	20 × 110	130	600–750	840	54

Usage in battles

The Type 99 Mark 2s are very "middle of the road" cannons in War Thunder, as they are not amazing at anything but not bad at anything either. Although they have gotten a bad reputation for poor damage output, the Mark 2's raw damage is quite respectable when aimed well. Being middle of the road weapons means that you can use them in many scenarios and they will perform their job amicably, but the usage style changes depending on what aircraft one is approaching. When engaging fighter aircraft, a quick burst to the cockpit or tail is generally enough to get the job done, but you might have to use more ammunition for heavier aircraft such as twin-engined fighters or attackers. When engaging bombers, the pilot must take a more reserved approach when attacking as a good amount of bombers that one will face can soak up damage like a sponge, so aiming at the engines and wings are crucial for preserving ammunition.

Your belt of choice should be the reliable Universal belt, as it provides the most balanced ammunition spread and a tracer for aiming. However, if you are familiar with the Mark 2's ballistics, the Stealth belt is an excellent choice due to the removal of the tracer round and an additional AP-I shell, allowing you to sneakily strike unaware enemies.

Pros and cons

Pros:

• Good all-rounder weapons that deal decent damage to all targets
• Typically carries a large ammunition load
• Hard to jam, able to fire continuously for nearly 10 seconds with crew skills
• Reasonably accurate
• Seems to excel in starting fires
• HEF shell is excellent and deals great damage

Cons:

• Has a tendency to spark
• Low rate of fire, nearly half of contemporaries
• Guns are usually mounted on the wings, creating significant convergence
• Mediocre ballistics

History

Around early 1935, Japan noticed that it was starting to fall behind in armaments as the 7.7 mm Type 97 and Type 87 machine guns became obsolete, and as such turned their gaze northwest to search for a solution. The Japanese Army sought to upscale their M2 Browning derived Ho-103 machine gun, which became the excellent Ho-5, but the Navy searched for a lighter cannon due to the emphasis on weight saving in aircraft. The Oerlikon FF became the weapon of choice and the IJN negotiated to produce the cannon in Japan, which was designated simply as E-Shiki. The E-Shiki was continuously refined and improved until 1941, when it received the Type 99 designation. Although inferior to the Army's Ho-5, it was the lightest aircraft cannon of the war at a mere ~23-27 kg thanks to its APIB action, making it the first choice for the Navy's new lightweight, carrier-borne fighter aircraft that would become the legendary A6M Zero. The early Model 1 cannon was based on the Oerlikon FF and was fed by a 60 round drum magazine, although this changed to a higher capacity 100-round drum magazine around 1942.

The Model 2 cannon emerged mid-1942 as a heavier alternative based on the Oerlikon FFL in response to the larger and stronger airframes of later Japanese aircraft that could accommodate larger weapons. The larger size, weight and more efficient cyclic action allowed for a significant increase in muzzle velocity, from 600 m/s to 750 m/s at the cost of a slightly lower rate of fire of 490 RPM in the earlier marks (something that was remedied in the later marks). The first mark used the same 60-100 round drum magazines as the Model 1 cannon, but this was changed to proper belt feeds that allowed for significantly more ammunition to be carried in Mark 3, the most common of the versions. The last mark to see service was the Mark 5, which introduced a number of improvements and innovations in the bolt and belt feed systems to achieve a much higher rate of fire of 750~850 RPM but saw limited use due to its late introduction in May of 1945.

Media

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

See also

Related development

• Type 99 Model 1 (20 mm)

External links

Paste links to sources and external resources, such as:

• topic on the official game forum;
• other literature.