What I've learned about Felarx evolution challenge 3
I saw this challenge and immediately thought there must be some weird meaning or trick to it, since the default chamber for non-incarnon mode has 6 shots.
Each "Pellet" is it's own hit, you can finish this with an unmodded Felarx, just hit the angel's head. The Felarx comes by default with 4 multishot and a magazine size of 6. So, Felarx has 24 potential headshots by default.
Just maximize shots with Multishot and more ammo. I did mine with no extra magazine size, just more multishot. If you use Hell's chamber it brings it to 8+ shots fired, meaning it goes from 24 potential headshots to over 48. Add more magazine size with Ammo Stock and/or Burdened Magazine and you can jump it upto over 100 pontential headshots. It's an easy enough Evolution, it just sounds confusing.
Also, you don't have to finish the mission for the evolution to count, you can join a mission "BLAM BLAM BLAM!" an Angel in the face and then just abort mission.