Pretty sure a few of those Shock Charge kills are from shooting an enemy Shock Charge and having the guy get killed by it, I've got about 500 Shock Charges used back from my ultra noob days. --- GG TREYARCH! http://www.youtube.com/watch?v=QPfj-JvI0XI
I believe if you set one off with an EMP grenade (like the enemy is standing on it when the EMP grenade goes off) you can injure them with it... That and if you're shooting them and set it off the SC can injure them as well. Since the SC takes a long-ass-time to shock you, it can kill them as you're in between shots.
Just my thoughts. --- GG TREYARCH! http://www.youtube.com/watch?v=QPfj-JvI0XI