[v18.5] Second Quick Slot

I have a grenadier I equip with nothing but grenades, even though his belt holds four different kinds of explosives I only have a single quick slot available to me, the second is always blank and does not react to right click.

I Believe the second slot is only for the extra clips for the primary weapon.

The top one is for grenades, the bottom one is for clips.

EDIT: Ninja'd by nutbarz