Well guys, The Ballistic Knife upgraded is AMAZING!,round 20+ only three knife stabs and they die, Its perfect for if your camping on a window, but also! upgraded when you shoot your knife at a "downed" person it will revive them instantly! , perfect!, i was on two windows the other day whilst my friends where covering the door, and i got 23 revives!, it was AWSOME! Also its a secret achievment if you revive someone with Them!