Do you have a youtube example showing the kill sound? The WW2 footage I found has a somewhat similar score popup to what I'm doing but I can't hear anything but bullets.Idk if you want a better video but when you hit with a bullet in cod, this sound plays:
Yeah repetitive positive sounds are really powerful. I need a sound for cubes exploding so I might just slightly modify that if it's your own kill.
I've been working on that too, although in my case it's lightning.
Its hard to explain how satisfying it is to hear it. COD would be quite a lot worse without it.
Edit: actually here's a good video of the sounds in action
Something like this for hits and kills would be great.