Coiled Watch champ threshold
Join a party. ALWAYS join a party when zerging, this way you share your party members’ tagging as well so you will always get the loot.
I can tell you from my own experience that you will get credit and loot if you hit the champ even 1-2 times right before he dies IF you are in a party and the other party members have been hitting it. I got this countless times when ktraining in eotm and lagging a bit behind the zerg to harvest, then getting to the objective right as the champ was almost dead and only managing to land 1-2 hits with my lootstick (1-2k dmg). I got loot every single time.
Always party up when zerging, I can’t stress this enough.