I dont see anything wrong with the buff hammer on guns. Even with the damage.
Like i said on another thread, we need to get the gunner to be as usefull as the engineer or pilot in all corners across all ships.
The gunners amount of ammo does not help him in every gun. It is a diminishing return because of his activity outside of a gun. While a single ammo can be reloaded at a time.
Ide like to bring up Ammo Combine, if gunners had a Fifth default selection of ammo that allows them to combine all of the stats and changes (even the diminish ones) from equiped ammo into one, then we would have a good use for the class. Some ammo types need tweaking then. Heavy clip and this other ammo i forgot about would need to have a nerf.