How did I know it was going to be about the sad elephant ifv lol

A 5.56 coax seems pretty anemic and borderline not worth it to me.

That does seem an odd choice. 

I wonder whats the rationale there, have the co-ax share ammo with the Squad LMG so the troops can steal the IFV's spare ammo if needed? 

gatnerd said:

I wonder whats the rationale there, have the co-ax share ammo with the Squad LMG so the troops can steal the IFV's spare ammo if needed?

Or "not enough volume to store a MG5 with relevant ammo"?

EmericD said:

Or "not enough volume to store a MG5 with relevant ammo"

Probably the more plausible explanation. 

I recall reading that it was something to do with keeping it within A400M transport limits, but I thought it was a mass thing rather than a volume thing.