I wouldn't mind if it was another engineer tool. An "Ammo Box" for example. When used on a weapon, it resets the "default" ammo to the loaded type. That way, I can run to a gun, load up my preferred ammo, and set it as the new default. Then I don't have to worry about hopping off the gun to do something else until the gun, or ship was destroyed. It also means that there is more reason for a gunner to take a new "default" and then conditional ammo, as no one has to worry about it reloading to standard anymore.
As it is a tool, it means I can't take any repair item, or the buff hammer. (Of course, I'm of the opinion that buff hammer should effect health and turning of a gun, not damage.)