Why? If you are in your own home and are legally defending yourself. Why not shoot them with a shotgun? You have 4 rounds that you can choose between buck shot or slugs, if you opt for a tactical model, you usually have about a 7 shot capacity. Add a side saddle to it for another 6 rounds of ammo on it. You have 13 shots available now to you. Why would you turn the best QCQ weapon available for home defense into a short spear? Tactically speaking, it doesn't make sense at all if you goal is to protect your home. If you are close enough to stab them with a bayonet, you are close enough to pull the trigger on them. If you need more than 13 shots at close range with a shotgun, then you need to spend more time out on a range running drills and understanding your weapon.