What's this Japanese cartridge case?

[charley777]

Greetings
Travelling abroad without my data lists.
Can anyone remind me what this cartridge case is?
55-60 × c120R x 66rim
Thanks very much

 

[Tony Williams]

It was used in a tank gun, and also in the Ho-301 aircraft cannon.

Correction - should be Ho-401.

 

[charley777]

Oh yes of course... the 57mm tank (and aircraft) gun
Haha, i even have one of these cases at home
Thanks Tony

 

[HAZORD]

@Tony Williams

Is the 57mm the largest caliber used in Jap aircraft, or are there larger ones?

 

[Tony Williams]

I don't know of any bigger guns which saw service.

Two experimental weapons were the 57 mm Ho-402 (much more powerful than the Ho-401) and the 75 mm Ho-501.

 

[HAZORD]

What was the case length of the 75mm round for the Ho-501?

 

[Tony Williams]

What was the case length of the 75mm round for the Ho-501?

Sorry, I don't have that. The only extra info I have is that the gun was a scaled-up version of the Ho-203 and 401. So presumably a short case, low-velocity weapon.