I figured this gun would knockout enemies (similar to Sandman, but they're sleeping instead) for like, 5 seconds. The downsides are that the enemy knocked out rapidly regains HP while KO'd, oh, and they take 75% less damage while KO'd, and you can only have 5 "bullets". This wouldn't make this a useless gun, just a gun you could use to get away if your spotted. (Oh, and a great anti-engineer gun too.)