does using the gamma burst not count towards them? because i have killed four at once with a gamma burst plenty of times or is it not working proplerly like plenty of things in this game. same thing happend to me with blind furybut i eventually got it somehow.

Kills from mission supports donot count. You have to actualy kill them.

Actually, I got my first "Psycho!" with 4 kills from a gamma burst and one kill via Feline. I'm almost certain that killstreaks count towards them.

kill streaks used to count before the latest patch, not anymore.