I would be suspicious of a lot of that stuff.
French 7.5 X 54 ammo should be 7.5 x 54 ammo regardless of which gun it is used in. Bullets should weigh the same unless one listing is for ball and one for tracer but then why is the heavier bullet in a lighter cartridge?
The Hispano HS. 9 cannon used a drum feed and not a belt, there are NO LINKS. The French, although they designed a belt feed for the HS 404 never got it into service. ALL French aircraft in service in the spring of 1940 used drum feeds on their HS 404 cannon so again NO LINKS. By the way, weight of an empty 60 round drum is substantial.
the RB in the cartridge designation is for rebated rim or rebated base.
The rim is smaller in diameter than the body of the cartridge.
I would note that the HS 404 used the 20x110 cartridge, the 20 Oerlikon used the 20x110RB, I am not sure what the HS 9 used.
BTW the R on the 7.7 x 56R stands for rimmed, see 20x99R in photo above.
SO the French section is a mess.
Some of the others seem OK but some of the German stuff seems a bit strange.
How on earth the short stubby 30 x 90 rb (2nd on left) winds up heavier than the 30 x 184B (belted and 1st sound on left) is beyond me.
For the Japanese what leaps out is that the 40mm caseless didn't use a belt, it used a box magazine, there was also no cartridge case so the projectile weight and total round weight is identical.
it was a rocket fired from a rifled tube that was sealed on the rear end.
595 grams is 20.988 ounces.
There may be others but I don't have time to pick out more than the obvious at the moment.