Board Thread:Unanswered Questions/@comment-26417223-20151122122232/@comment-25045164-20151122124241

From my experience, it works this way:

Say that an enemy has 1000 points, if you hit all the way till 75%, you wouldn't get 750 points. You would get only 375 points (just an example. I don't know the real percentage for this). If a guy comes in for a kill and deal the remaining 25%, he would get 625 points.

So, it's back to Viper's Ace Seminar: You have to make the kill to reap the rewards.