This is definitive proof of the bombload capability for the Ki-102, yet the report was accepted two years ago. Hopefully we get it soon
It took us a while to get the practice shell lol. Hopefully we can find the proper ammunition for this gun
Is there any point to it though?
Whats there to hit with a 57mm Practice shell that penetrates as much as a .50cal?
Took a second look at the ki102, what the hell is a Practice shell? It is available both on 20mm and 57mm… It ‘ruins’ Stealth & Default belts
Also hitting with 1 20mm AP-T won’t do damage to modules, and 1 57mm will yellow breech
Well shells for practice. Usually just the same as the normal shells, but not hardened, false fuzes and no filler. Both IRL and in game also used as an cheap ersatz for when no AP rounds existed or were available.
In game, tho just badly implemented. Because while IRL softer shells would dump more enegry into the target, in game it doesnt, because its based on remaining penetration, which is for Practice shells generally already lower.
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Even with proper implementation I don’t really see a use case to fire 57mm practice rounds at any target.
They are supposed to be like an AP shell substitutes but they can’t really pen anything that you couldn’t pen with 20mm AP.
World was a better place when it just had HE as only ammo type.
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Yes and no imo, shure especially on that plane and at that BR it seems rather redundant, however it can be fun (or just for the funny) as well as i might load the 20mm with HE shells primarily for Air to Air, and load a mixed belt for the 57mm gun against soft and open topped targets. Also works for the Ki-45 Tei, which has as offensive armarment only a 37mm Ho-203 gun which also only fires HE and Practice, tho at a BR of 1.7. (But even it is rather really weak, dont expect anything more than going through the roof, but the speed of the plane shure does help.)
I think overall its a good addition, simply because even tho it is a niche, its still an addition.
But 57mm HE overpressures while 57mm Practice probably doesn’t pen an enclosed vehicle anyway
I measured the dimensions from the photo to verify whether it can accommodate two 250kg loads.
To begin with, the IJA’s 250-kg bomb has a diameter of 300 mm.
If the spacing between the bomb racks is narrower than this, it is physically impossible to carry two 250-kg bombs.
爆撃教育規程案に対する意見の件
Secondary sources indicate that the fuselage width of the Ki-102 Hei is 1,050 mm. Although the Hei has a wider wingspan, the fuselage likely remains unchanged.
Based on this information, I measured the photos using CAD software.
(Since working at actual scale would be too time-consuming, I’m drafting at a 1/1000 scale.)
Rack spacing: approx. 330 mm
Since this drawing is based on photographs, it is not definitive. Furthermore, even if the dimensions were accurate, I cannot say for certain whether a 30mm clearance would be sufficient in practice.
In conclusion, it would be impossible to carry two 500kg bombs, while carrying two 250kg bombs might be possible, though I cannot say for certain.
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By the way, if you arrange the 250-kg bombs based on the illustration in the secondary source, they will overlap.
I also measured the dimensions from the photos to see if it could carry 4x 100kg bombs.
Spoiler
The manual specifies “2 x 100kg bombs”
Translation No. 80, 18 July 1945, KI-102 handling instructions. Report No. 3-d(65), USSBS Index Section 6 (文書名:Records of the U.S. Strategic Bombing Survey ; Entry 46, Security-Classified Intelligence Library. 1932-1947. 65 ft = 米国戦略爆撃調査団文書 ; 各種日本関係情報) (課係名等:Intelligence Branch ; Library and Target Data Division) (シリーズ名:CINCPAC-CINCPOA: Special Translations) - 国立国会図書館デジタルコレクション
In this photo, you can see the position of the front end of the bomb rack.
It is roughly at the same level as the canopy frame.
This photo shows the mounting brackets for the bomb rack.
Although they appear to be located in the middle of the rear canopy frame, the angle of the shot is quite oblique, so we can infer that the bomb rack—which is positioned near the center of the fuselage—is actually slightly further forward, roughly at the level of the frame in front of the canopy.
According to the manual, the Ki-102 has an overall length of 11.45 meters.
Based on this, I adjusted the scale of the drawings in the manual using CAD software and measured the length of the bomb rack, which came out to be 2.33 meters.
(Drawn at a 1/1000 scale)
Based on the above, I adjusted the scale of the bomb rack diagram in the manual and measured the spacing between the solenoid sections, which yielded a result of 1.59 meters.
Since the length of an IJA 100-kg bomb (including the fuze) is 1.382 meters, it is believed that it can be mounted without any issues.
(Even if the spacing between the bomb racks were about 0.1 meters shorter, there would still be ample room.)
Since the manual lists the 500kg bomb as “special equipment,” perhaps the design was intended to have a maximum payload of 250kg.
(In other words, 100kg x 4 is considered “special equipment.”)
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