Disregarding the previously loaded bullet found on the kitchen surface, I have considered the possibility that the other five had been previously loaded and unloaded, loaded again, and they then stayed in the magazine. Perhaps Jeremy was mistaken when he said the magazine was empty and there were five bullets in there. He could only have then loaded another five at most.
Of the five bullets which had been previously loaded, two were fired in the bedroom, one was fired in the kitchen, and two were fired in the children's bedroom.