Only one of each ammo talent may be active on a single weapon at a time.
Incendiary Ammo: As a swift action you may activate Incendiary ammo on one ranged weapon you are holding, if any of the next 10 shots fired cause an organic target damage they'll take 1d4 (rolled on activation) damage per round for 5 rounds.
Armor Piercing Ammo: As a swift action you may activate armor piercing ammo on one ranged weapon you are holding, the next ten shots fired ignore 2 points of damage reduction.
Cryo Ammo: As a swift action you may activate Cryo Ammo on one ranged weapon you are holding, if any of the next ten shots fire exceed a target's damage threshold then they are cannot take an action on their next turn.
Disruptor Ammo: as a swift action you may activate Disruptor Ammo on a weapon you are holding, the next ten shots deal double damage against Shields, Droids, and Synthetics.
Dual Ammo: You may have 2 ammo abilities activated at the same time; prerequisites: 2 talents from the ammo specialist talent tree.