Seen this is present a few times in this forum, even as far back as PTR, but no visibility. The momentum stacks for using a primary skill DO NOT trigger when using the Calamity legendary power.
Even shooting off to the side (away from mobs) rarely adds momentum stacks, unless absolutely no mobs are present.
Reading up on Calamity, it sounds like the marked for death is applied before the damage is dealt? If so, this may be the issue - as it is not classing the attacks as primary skills for GoD to trigger.
Pretty sure this was deliberate on Blizzards/Buzzards part and as happened when Diablo III first started the monk and barb players are going to say Demon Hunters are too OP Nerf the out of the whole class, Anyway who cares if they can’t use an item they like
I did find a work around for using Marked for Death by itself,About every minute or so you have to pause and use Primary Skill(in this case hungering arrow)or when you get a real tough boss Marked for Death can come in handy just until you start strafing again
out of the whole class, Anyway who cares if they can’t use an item they like 