You know guyes it looks really funny - just like to let F-15 take only 2 sidewinders to make it lighter.
I usually use 3x20mm at 109G10 - even it makes you heavier. It lets you more chances to kill your target - 3x20mm can kill almost any fighter plane in one pass when taking 1x20mm makes you lighter but you should make much more time your guns on target.
Every BnZ fighter need good firepower.
And I tell you more if 7mm really has no good effect then 13mm MG of 109 quite good weapon - I've made a lot of kills with 13mm MG when I finished my 20mm ammo. More then that it is very usefull to make pisichologic effect on your enemy.
When he sees bullets running from 800 yards - it forces him to make some offencive manuvers - and let you close on him. Even you will not get kill from such distance you might force him to make brake turn and then catch him.
So take an ammo it allways helpfull. You finally have not only get on your victim 6 you have also to kill him before he get some help. And few pounds of ammo that is not the thin that will make 109 turn better then spit
