CV90-40mm

[Imp]

Not got time for a thorough look so dont take as gospel but link to specs for CV90 35mm version.
http://www.baesystems.com/BAEProd/groups...ibroch.pdf

Upon looking further fairly sure Bofors is now part of a huge arms buisness called BAE systems & one of there companies makes Bushmaster 3 hence probably adapting programable ammo though
Rheinmetall is a seperate Co. There are references to 40mm as Bushmaster IV, 57mm Bushmaster V? think this aimed mainly at ship close defence due to weight etc.

Found some info on diffrent shells used by MKIII possibly the programable vs MkIV. There is still a diffrence in ammo use though nowhere near as bad & AA mode is the biggest diffrence. Unsure why you think MkIII more accurate could not find info on & data vs new ammo types does not seem to support this. At longer range the diffrence in ammo use becomes worse suggesting the reverse.
The 40 has 1,100 tungsten-pellets weight unspecified, probably space for a clever fuse to causing better/ more varied dispersal patterns.

A thought you may have thought more accurate as refering to version used in aircraft as that was the only one with programable ammo I had heard of, developed for (in use by?) US Gunships.
You cannot compare this gun with ground version diffrent rates of fire barrel length muzzle velocity etc.

As to which ones best no idea but as the video says the 40 can defeat ALL IFVs frontal armour & MBTs with flank shots.