Mayan- Okay, you want a number? The American Academy of Pediatrics did an exhaustive study on this issue. One of their findings was that for homwowners who own guns, it is 43 times more likely that a person known to that family will be shot by that gun than an intruder would be. For this reason I assure you that your pediatrition will tell you in no uncertain terms NOT to keep a gun in the house.
Any Rav who says otherwise is a dope.