Searching for J2M4/5 (TYPE5 cannon) details

[MeSpit]

I found a very special version of J2M, which has 30mm guns, and it looks like type 5, but I can only find some pictures. I'm also searching for general stuff, tech, usage manual, and Blueprints. especially regarding its weapons.

 

[fubar57]

PM sent

 

[pb43]

I found a very special version of J2M, which has 30mm guns, and it looks like type 5, but I can only find some pictures. I'm also searching for general stuff, tech, usage manual, and Blueprints. especially regarding its weapons.View attachment 854385

The J2M was never given a Type number designation! If it had it would have been Navy Mitsubishi Type 2 Land Fighter. The long designation that was given is plain Navy Mitsubishi Land Fighter Raiden. Or are you talking about the Type 5 Cannon? Type 5 cannon - Wikipedia.

See also:-The Japanese Navy also showed interest in 30 mm cannon. The Type 2 was a scaled-up Oerlikon gun, sometimes erroneously described as a copy of the MK 108. It never became a standard service weapon, although it was tested on a number of aircraft and formally adopted. A better alternative was available, the Type 5, an entirely original design. Though fairly heavy, this was a powerful weapon with a good performance. If the war had laster longer, it would have become the standard weapon, fitted in fighters such as the Kyushu J7W Shiden. But it saw service in only a few aircraft, being wing-mounted in the Mitsubishi J2M5 and installed in upward-firing installations on some nightfighters, such as the P1Y2-S.

 

[AerialTorpedoDude69]

According to Japanese Wikipedia's entry on the J2M5, it was optionally equipped with the Type 5 30mm cannon. The number type of the J2M5 was 33 and there didn't seem to be a subdesignation for 30mm-equipped J2M5.

In the spring of 1945, the Type 33 equipped with two Type 5 30mm machine guns were also deployed in the same air[41]​.

One ace had scored some victories using a Raiden equipped with the Type 5: Sadaaki Akamatsu, the notorious bad-boy of the IJN, who was also one of the most experienced fliers in the world. I might be misremembering, but I believe Akamatsu was recorded firing the 30mm cannon in anger on at least one occasion against fighter aircraft. I believe the victory was against Hellcats in 1945 during the February carrier raids which were intercepted over the Kanto plain. But it could also have been against Mustangs as well. I believe the Mustang in question was flown by Rufus Moore, as described in this article. The best English language biography of Akamatsu is an informal piece.

Something new that was apparently recently added to Wikipedia is the mention of a scaled-down version of the Type 5: a 20mm version. It had a muzzle velocity of 900m/s, RoF of 700 round/min. The prototype Type 18 20mm cannon was found at the Kentucky Military History Mueseum.

Experimental Type 18 20mm Fixed Machine Gun

The "Experimental Type 18 20mm Fixed Machine Gun" was developed as a scaled-down version of the Type 5 30mm Machine Gun. It was a high-performance weapon, weighing approximately 40 kg, with a muzzle velocity of 900 m/s (1.2 times that of the Type 99 Model 2 gun) and a firing rate of 700 rounds per minute. The required performance specifications were established in September of Showa 18 (1943), shortly after the completion of the first prototype of the Experimental Type 17 30mm Fixed Machine Gun.

The ammunition was shared with the Type 99 20mm Fixed Machine Gun. Although the cartridge case was shortened by 3 mm compared to the Type 99 Model 2 gun, the propellant packing density was increased, raising the propellant charge from 21.6 g to 34 g. Design and prototyping were conducted by the Naval Air Technical Arsenal, and the first prototype was completed in January of Showa 19 (1944). Aerial testing using a Zero fighter was carried out in August of the same year.

However, by December, the practical deployment of the Type 99 20mm Model 2 Gun Mark 5, which achieved a firing rate of 720 rounds per minute, was on the horizon. As a result, by around March of Showa 20 (1945), the prototype development was effectively halted and eventually canceled.

Recollections from involved personnel indicate that the development of the Type 5 30mm Machine Gun benefited from insights gained during this project. In 1989, a prototype of the Experimental Type 18 gun was discovered at the Kentucky Military History Museum, alongside a Type 5 30mm Fixed Machine Gun Model 1, serial number 1724, manufactured by the Toyokawa Naval Arsenal.

 

[pb43]

According to Japanese Wikipedia's entry on the J2M5, it was optionally equipped with the Type 5 30mm cannon. The number type of the J2M5 was 33 and there didn't seem to be a subdesignation for 30mm-equipped J2M5.



One ace had scored some victories using a Raiden equipped with the Type 5: Sadaaki Akamatsu, the notorious bad-boy of the IJN, who was also one of the most experienced fliers in the world. I might be misremembering, but I believe Akamatsu was recorded firing the 30mm cannon in anger on at least one occasion against fighter aircraft. I believe the victory was against Hellcats in 1945 during the February carrier raids which were intercepted over the Kanto plain. But it could also have been against Mustangs as well. I believe the Mustang in question was flown by Rufus Moore, as described in this article. The best English language biography of Akamatsu is an informal piece.

Something new that was apparently recently added to Wikipedia is the mention of a scaled-down version of the Type 5: a 20mm version. It had a muzzle velocity of 900m/s, RoF of 700 round/min. The prototype Type 18 20mm cannon was found at the Kentucky Military History Mueseum.

Try not to confuse everybody. Do you mean J2M5 Model 33? (not Type 33).

 

[AerialTorpedoDude69]

Try not to confuse everybody. Do you mean J2M5 Model 33? (not Type 33).

According to the link, it's exactly what you wrote: the model designation is Raiden Type 33. The quad 20mm version is known as the Raiden Type 33 Ko, written in Japanese as 雷電 三三甲型. But I don't see the correct submodel designation for the 30mm cannon-equipped model, which suggests that the 30mm were only installed on a trial basis and these were never introduced into the production line.

The page also mentions that all four 20mm were replaced with the pair of 30mm Type 5 cannons. I don't know if that's true but M MeSpit the Japanese Wikipedia pages have original sources in them. It's a good first place to begin a search for schematics and blueprints.

There's also this War Thunder page. It's a shame they don't publish their sources:

J2M5 30mm - War Thunder Wiki

old-wiki.warthunder.com

 

[SaparotRob]

Nice bit of sleuthing.

 

[MeSpit]

Try not to confuse everybody. Do you mean J2M5 Model 33? (not Type 33).

I'm not sure if it is J2M5 or J2M4, yeah, but for Warthunder, that is J2M5, but thanks for mentioning, I will edit the title again.

 

[MeSpit]

The page also mentions that all four 20mm were replaced with the pair of 30mm Type 5 cannons. I don't know if that's true but M MeSpit the Japanese Wikipedia pages have original sources in them. It's a good first place to begin a search for schematics and blueprints.

There's also this War Thunder page. It's a shame they don't publish their sources:

I believe it can choose to replace just 2 or 4*20mm cannon, as the title photo shows that J2M can still have 2* type 992 cannons, and according to the"Japanese Air Weapons And Tactics, 1947 (U.S. Strategic Bombing Survey) : Military Analysis Division : Free Download, Borrow, and Streaming : Internet Archive

2​

" at least we have J2M4 with 2*30 and 2*20mm version

 

[MeSpit]

the Japanese Wikipedia pages have original sources in them. It's a good first place to begin a search for schematics and blueprints.

I have searched for that, but it does not work. All the documents just mentioned We do have some J2M which are equipped type2/5 30mm cannon, but no details.