Hey LeapingNinja,
to do what you want here is a simple explanation:
trigger#1 (the triggering trigger)
activated by whatever
condition:this
activation field: shotgun = true
Trigger#2 (the action bit)
activated by: set to nothing
condition: shotgun
activation field: whatever it is you want to happen
*******************************
So you stated that the variable/boolean "shotgun" was true in the first trigger so the second trigger fired once shotgun = true.
Hope it helps.