For barrage, In the opening, I'm not willing to wait for straighter shot procs because it only triggers when I start using heavy shot. It's cooldown time wasted if I wait for refulgent.
However, in the subsequent barrage cd, I sometime save my staighter shot proc when raging and barrage is almost up.
But, I prefer not to wait for proc to use Raging+barrage even after the openning. Well, I don't like wasting cooldown time @.@