The HUD desperately needs an indicator of what ammo type you currently have equipped. Unless you are some rainman-esque savant who can memorize how much of each type of ammo you have at any given time, there is no way to tell which type you are using. It would be nice if there was an indicator next to the ammo count to let you know what was what. Nothing for standard ammo, AP for Armor Piercing, HP for Hollow Point, B for Bulk, OC for Overcharge, FC for Full Charge, etc.
What do you think?
After changing ammo enter your weapons inventory move your mouse over your equiped gun and in its descripion it tells you which ammo is equiped,
LOL alternativly you could just look next to the condition bar of your weapon the ammo types indicated there unless its normal ammo.