Type 99 Model 2 (20 mm)

Description

The Type 99 Model 2 was the main 20 mm aircraft cannon for the Japanese navy during WW2, replacing the earlier drum-fed Type 99 Model. 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 the Model 2 and the Model 1 consist of a longer barrel and a longer chamber. 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 opposed to the Model 1's 600 m/s.

Vehicles equipped with this weapon

Vehicles equipped with this weapon
Fighters
A6M	A6M3 mod. 22Ko · A6M5 · A6M5 Ko · A6M5 otsu
A7M	A7M1 (NK9H) · A7M2
J2M	J2M2 · J2M3 · J2M4 Kai · J2M5
N1K	N1K1-Ja · N1K2-J · N1K2-Ja
Twin-engine fighters	J1N1 · J5N1
Bombers	B7A2 · G8N1 (Defensive)

General info

The Model 2 cannons have a rate of fire of 490 RPM, implying the variant in game is the Model 2 Mark 3, as the later Model 2 Mark 5 cannon had a sustained rate of fire of 620 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 150 to 250, which allows for a significantly large ammunition pool in its traditional quad or double mount setup.

Available ammunition

• T - Standard tracer shell
• FI - Fragment Incendiary shell
• AP-I - Armour Piercing Incendiary shell, second most common among belt setups
• HEF - High Explosive Fragmentation shell, most common among belt setups
• HEF-T - Tracer variant of HEF shell, slightly higher muzzle velocity but lower explosive power

Belts:

• Default: T, FI, FI, API
• Universal: HEF-T, HEF, HEF, AP-I
• Ground Targets: AP-I, AP-I, AP-I, AP-I, HEF, HEF-T
• Tracers: HEF-T, HEF-T, HEF-T, HEF-T
• Stealth: HEF, HEF, HEF, AP-I, AP-I

Comparison with analogues

Give a comparative description of cannons/machine guns that have firepower equal to this weapon.

Usage in battles

Pros and cons

Pros:

• Good all-rounder weapons that deal decent damage to all targets
• Typically carries a large ammunition load
• Lower rate of fire allows for guns to last longer
• Hard to jam, able to fire continuously for nearly 10 seconds with crew skills
• Reasonably accurate
• Seems to excel in starting fires

Cons:

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

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 had negotiated to produce the cannon in Japan, which were designated simply as E-Shiki, and were continuously refined and improved until 1941 where they 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 kilograms 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

An excellent addition to the article would be a video guide, as well as 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

Paste links to sources and external resources, such as:

• topic on the official game forum;
• encyclopedia page on the weapon;
• other literature.