A friend gave me 20 empty cases of the middle type. He said they were 7.7x58 Arisaka cases of Norma make. Given the appearance I set them inbetween a .30-06 case and a 7.7x58 and the story became clear. Somebody put a .30-06 chambering reamer in a Type 99 chamber and fired 7.7x58 in it. It produced a perfectly fire-formed short neck .30-06 case.
Lots of Type 99 Arisaka were so treated so it behooves the shooter to pay attention and exercise due diligence in firing these guns. In this case it wasn't an unsafe action, though many similar sorts of circumstance it could be very unsafe to introduce mis-match ammo.
Dutch
Series 33