I am completely new to all types of firearms. I purchased a Mossberg 12-gauge semi-auto 930 SPX "Tactical" for home defense and I expect to pick it up this week. The homes in my Southern California neighborhood are wood frame stucco and built close together. On one side of my house my neighbor is only 15' away. I know not to use slugs and/or probably buckshot, but how far down to I need to go to stop a bad guy in my home without risking my neighbors? #6, #7, #8? The furthest distance I would need to shoot inside my home is about 30' Appreciate any feed back as this is all new to me.