I would be more concerned with whether shooting the pedophiles in question is the correct course of action. You are either putting the child in mortal danger - if , as mentioned above, the kidnapper is close - or dispensing vigilante justice if the kidnapper is a safe distance away from the victim.

I'm having difficulty imagining a realistic scenario in which bringing guns into the equation actually helps the child. It seems more likely to me that the OP's endgame here is to murder a pedophile and get away with it.