So if your aware, IRL the installment of a hair trigger on an semi auto rifle, it enables you to fire as fast as your little finger can squeeze the trigger. This is not the case in game, hair trigger on the multi tool only let's you shoot through the half pull off your R2 trigger; however due to the guns rate of fire, it makes no change to this Exotic rifle. Even less change if you've switched R1&R2 .... Actually it makes the perk useless if you've switched those buttons... Wait what's the purpose of hair trigger?