It works as intended, and does marginally (+8%) increased crit damage when active. It’s only active on a single burst where one or more shots hit the body, then one or more shots hit the head, and it only applies to those bullets that hit the head. It’s very situational, and there is no scenario in which you get more damage by intentionally dropping a shot into the body. I would not expect too much from this perk, and cross fingers to get any other perk.

This is not how headseeker functions, so this is not a bug. Headseeker only applies to bullets within the same burst. In your Go Figure example, landing ANY NUMBER of bodyshots (1-3 of the 4) will cause the rest of the bullets to do more precision damage. Essentially, headseeker is supposed to be a good perk to mediate lost damage at range. The idea, and why it's so good in crucible, is that if you are in a gun battle, or at extreme range which makes hitting the head more difficult, headseeker helps to compensate damage loss. Rather than aiming for the head and hitting 4x 27, headseeker with 2 bodyshots will hit 2x 17 + 2x 32 (These are arbitrary numbers, not in game right now). The idea is hitting 2 bodies and 2 bonus precision damage shots is greater than base 2 body 2 head. If headseeker functioned across bursts, it would make 2 bursting in crucible WAY too consistent at range, causing players to have bonus damage almost all the time, and most likely bursting to the body intentionally to have a follow up burst that can do upwards of 120 damage. In other words, your interpretation of headseeker is like Destiny 1 luck in the chamber but for bursts.

Its not working because I only works if within the same burst you hit a body and head shot. It barely does anything though so not much difference.

I have this issue too. I have a bygones with headseeker and rampage that I tested pretty extensively to see if this was a good roll. Rampage made a notable damage increase, but headseeker was extremely finicky. Even within the same burst, it almost never popped. I only saw the precision damage increase once, and it was only about half the damage as one stack of Rampage would give. Pretty lack-luster for what should be a staple perk for pulse rifles. I would like to see if anyone has had success with it though. EDIT: After posting this, I decided to give it another go and it worked fine... for awhile. And then it stopped working again. But it started working again after I swapped to a different kinetic weapon and then back to it. It does only pop within the same burst though. That, I know. It just selectively decides to stop working for some reason? Idk. I'm gonna keep messing with it and see what I can come up with.