FPS UI ammo display problem

Hey guys,

So the only thing left for me to get my guns working is to display the ammo count properly, and im quite lost on this. So i have a class called Firearm and my guns all inherit from that class. The idea is to display the correct ammo count of the gun im holding. On my character controller i have a GameObject called curGun, this is what determines what gun im holding. What i need to do is have the UIManager access the curGun that the player is holding and have it display the curAmmo of that weapon. Any ideas?