Don't go overboard with ammo, even if I hold more than I really need I don't believe that there is any need for that.

I have participated in a few wars and at first I would carry so much ammo that by the time we went into combat I was to tired to really put up a good fight...... what to do?

I would carry only 30% of what I just to carry and then I would take the ammo from the fallen ones from either side.....and the same for field equipment.