Re: Always running out of ammo
Certainly the big shields and small clips create more ammo pressure.
They also slow down the time-to-kill pace a bit, which makes the game more strategic - which is a good thing.
Try always taking weapons of different ammo types, and choose what weapons to carry based on the ammo you find, rather yhan always preferring gun-x even when you only have 2 clips of ammo.
Watch pro streamers, they don't seem to struggle too much with this.