A rarity, close up pictures of the Ho-155 30 mm guns emplaced in a Nakajima Ki-84 Army fighter.
That looks like a pretty effective muzzle brake!
It does, a little more information about this design.
Had WW II continued into 1946, the IJA 30 mm Ho-155 Browning machine cannon (often mis-designated Ho-105) would have become first line anti-bomber armament in IJA fighters and interceptors. It was starting to be used in early 1945, if only on a trial basis, and gun production was well under way. The four images attached, though of varying quality, show the evolution of this gun. They are approximately to scale, and are aligned to one another on the belt feedway.
Nice “salatgurkes” :shock:
The case was 30x…117 mm ??, not sure.
Yes it is a 30 x 115 … but I have heard of 116mm cases, too.
Any idea of gun system – looks like an browning system.
Hi.
The designation “Ho” indicates that it was a Hochkiss system machine cannon…
Yours
tom! 
According to this was a Browning type so I suppose is operated by short recoil.
http://www.j-aircraft.com/research/30_mm_ho155_browning.htm
The designation “Ho” indicates that it was a Hochkiss system machine cannon…
That is funny I tough it was a japanese word.
“HO” is a japanese character and used to ID aircraft guns and ammo. Nothing to do with Hotchkiss. Very similar to the “KI” character used to ID army aircrafts.
These Ho 155 gun is more a Browning copy I guess.
Ho is ホ in japanese.
Hi.
sometimes it´s necessary to think and look before writing.
“Ho” stands of course not for Hotchkiss but for gun. :oops:
I stumbled on the following article on the Ho 155::
Yours
tom!
30x114 is the cartridge designation I’m used to.
There were (at least) two different models of the Ho-155: the Ho-155-I had the squared-off receiver shape, weighed 50 kg and fired at 400 rpm. The Ho-155-II had the more sloping shape, weighed 44 kg and fired at 500 rpm.
The army used a 37mm gun too. The Ho 204. It was used f.e. in the Ki 46 III Dinah. I still look to find more fotos.
The gun weights about 130 Kg, muzzle velocity 710m/sec and a rate of fire 400 rds/min. The design was started as an anti tank gun.
The cartridge was a 37 x 145.
This is another scaled-up Browning.
I doubt that it was ever intended as an anti-tank gun: that may be the Ho-203, a 37mm gun which used the same ammo as an anti-tank gun.
Well, we all need documents for our threads. These japanese document is a crude translation and I will ask a japanese friend for a new better translation.
These document mentioned that the gun was developed as an anti tank gun -used in gondolas under the wings. Later it was used elsewhere of course.
The cartridge is a more or less complete new developement.
The Ho 203 used a 37 x 133 R cartridge originally made for a small trench gun.
The tank and anti tank round is a 37 x 166 R.
Beautiful information and pictures boys, interesting the “japanese Schräge musik”, keep up the god job 
!! step by step we are uncovering this little known topic.
I find a little picture of the Ho-204 37 mm, “horsecollar” feed autocannon. it remember me the loading system in the Airacobra gun.
Oh, an airborne anti-tank gun - that’s possible, I suppose, but I think it is unlikely because the performance of the cartridge was quite low, and armour penetration would have been limited.
The Ho 203 used a 37 x 133 R cartridge originally made for a small trench gun.
The tank and anti tank round is a 37 x 166 R.
Not quite - the 37x134R cartridge was actually developed for the Type 94 tank gun. The Type 94 anti-tank gun, and the Type 98 tank gun, both used the 37x165R cartridge. So did the Type 94 manually-loaded aircraft gun fitted to some Ki-45 planes (I used to think this used the 37x134R, but I was wrong).
Edit to add: the Ho-203 used yet another round, the low-velocity 37x112R.
No, that’s the Ho-203.
No, that’s the Ho-203.
You are correct this jap guns topic is beginning to lost me. :rolleyes:
So many cartrigdes cases for the same caliber…
The list of japanese trial aircraft guns fills two pages :mrgreen: