Because it would appear AH gun lethality is more dependent on velocity at impact then chemical energy.
Beyond 240 yards the MGFF (type 99 mk 1 as well) loses a large amount of lethality. Which at least to me would seem incorrect in that its chemical / explosive content doesn't change as it moves down range. All it needs is enough velocity to penetrate the aircraft skin.
With most non HE / Mine rounds their destructive energy is linked to kinetic energy which is "used up" as it travels downrange . With MGFF/M and HE / Mine rounds in general their destructive energy is stored chemically so it's retains most of its lethality as it travels downrange.
To be honest though not every round in the belt was a M-Geschoss (mine) round. I know AH doesn't model "belting" and uses some sort of "hybrid" fomula.
The MGFF with its low muzzle velocity made it harder to hit with (long flight time, more drop etc...) when comparing it to say a .50 cal or hispano. They way you defeat this is just to get inclose where you can't miss. This is totally separate from losing lethality down range.
Unfortunately in the AH main where the 109E-4 (110C-4/b; atleast the C-4 has plenty of mgff
) fights a mostly late war plane set your ability to get inside 240yrds is limited and as such your when you do have an opportunity to land hits the mgff just isnt lethal enough (in general) to get the kill.
When you fight the Hurri 1 or spit 1 its "lethal" enough to make the fight fun. In the main I always found it to frustration.
Its the same with the a6m2. When facing faster, sturdy aircraft like USN planes at times it gets more then frustrating.
The mgff on the A-5 just adds more weight for little benefit in lethality. You are better off just taking the 2 inboard mg151/20mm.
