when playing GOW online multiplayer if i get a guy down and continue to shoot at him it makes a strange noise and the bullets have no effect on them does anyone know the reason for this.

I noticed this earlier tonight playing execution on Mansion. Only happened a couple times, only seemed to happen with the shotgun, and meleeing the guy still killed him. I guess it's a new(ish) glitch.

well you guys are playing execution. you have to run up to them and kill them in exectution. so you have to curb stomp, shoot them with a pistol at close range, shotgun them (from a little farther than the pistol), chainsaw them, melee. you just have to be close. easy way to get your execution achievement though (as long as the bleed out time isn't really short, ie. 5 - 10 secs)