Yeah. The way COD does kill confirmation is the most satisfying for me. Number pop-ups and a nice satisfying sound.
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.
It's not the end of the world if you don't have it but it's satisfying and useful to have that certain sound to confirm your kills.
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.
Also when bullets make contact
I've been working on that too, although in my case it's lightning.