Do you have a pump shotgun?

If so get an 18.5 inch barrel and use it as your home defense gun. Use 2 3/4 inch shells firing a load of #4 buck shot. It will give you a much bigger margine of error when shooting at a home invader and the #4 buck will not over penetrate into other houses.

Bird shot, like #4 shot, also works extremely well at close range like inside your house and is very safe for not penetrating walls.