think about it... you are trying to pick a round that will penetrate a person, causing damage to internal organs, in the hope that they will stop their attack on you or your family. in order to do this is must go through skin, muscle, bone, and cartilage.
your walls are made of Sheetrock, and the occasional pine 2x4. this is much easier to go through than the skin etc. discussed before. So anything that is useful for defending yourself will unfortunately penetrate walls, often many of them.
If you absolutely can not risk a round penetrating through the wall, perhaps you should look at a taser? they don't use the aforementioned organ damage to stop an attack, and, when effective, can stop someone in their tracks. unfortunately they have many shortcomings that make them undesirable in many situations. they have a short range, if they fail, they fail miserably, they are very slow to reload, etc.