I've noticed (mainly in pvp) when I use the longer version of the archery snipe it does less damage. Even if I use aim and build up, the damage actually goes down. I used BU and aim and did the long snipe and it did 126 damage, but when I used blazing arrow without bu and aim it did 178. Fast cast does the correct fast cast damage, but the slow higher damaging version actually does way less.
I've heard from other players that Assault Rifle has the same problem.