Type 86, Type89, Type 100…All "Aircraft MG "designs.
The Type 86 (1926) design was an initial Modification of the Nambu Type 11 (1922) gun, to use 6,5mm ammo, in an aircraft role with a Magazine. Rarely seen,
and can be considered a “Prototype” ( there is one in Beijing, I think). The Japanese Army-Airforce had, Like the Navy, Imported a quantity of Vickers, Lewises, and Ammunition to experiment with,in the 1920s, and whilst the Navy went with the Vickers and Lewis (in .303 (7,7x56Rimmed) the Army-Airforce stuck with Nambu’s designs, and made a “Beefed up” semi rimmed 7,7 case (the Type 89) which eventually morphed into the Type 92.(Army).
The Type 89 Flexible (Single) is a common Observer’s gun for aircraft (Pan magazine similar to Vickers K or Degtyarev DT28)
which is chambered for the then New 7,7x58SR Type 89 ammo ( 168 grain proj), copied from the 174 grain .303); The Type 92 Improved the Ammo for ground Use ( also Nambu)…after about 1936, ammo for both was the same M92 Ground Loading.
( Packets of 50 rounds are so marked, and this ammo is Clipped)
The Type 89 (Twin) was the gun fitted with the “Fan” chain link clip magazine, which sat on a “snowshoe” type frame on either sides of the two (Mirror Image) Guns. The ratchet feed mechanism was the same as that used on the Type 11 Hopper)
Type 100 (both Single and Twin guns ( again, examples in Beijing Museum) were supposedly chambered for the Type 99 Rimless ammo, although one suspects the bolt was cut out to use either Type 89/92 and Type 99 ( as happened with the Type 1 Heavy strip-fed Ground Gun.)
I have a Type 89 Single Flexible…The Pan holds 67 Rounds, and could be mistaken for a Vickers K magazine, except for the Diameter.
Making Blank ammo for it has been another matter, which I won’t go into here.
Type 89/92 stripper clips have no side lugs, and are slightly wider than normal Type 99 clips.
Interesting the Dutch Vickers Variant… Nice one.