I think the best idea would be, leave the house, one in the chamber, come home, empty chamber. I just cant see a situation where I have locked doors and loud breaking windows, where I wont have enough time to rack the slide.. I mean it takes a 10th of a second. Out on the street, if something happens, you could have NO warning. so one in the pipe...
Ideas??
This is my thoughts exactly, just have to be aware of where you left it.