"A sawed off shotgun makes a great home defense weapon because the shorter the barrel the wider the projectile spread pattern. A wide spread pattern gives you a better chance of hitting a armed intruder and stopping him from shooting you. The problem has been sawed off shotguns are illegal. The barrel has to be eighteen inches to be legal. We have found a way to get the wider spread pattern of a sawed off shotgun without breaking the law. Our proprietary cone shaped eighteen inch barrel with a three inch round or oval muzzle provides the wide pattern legally. It looks something like the old blunderbuss that pirates used, but works a lot better. It is perfect for home defense because there is less chance of missing in the panic situation created by a armed intruder in your home. Also the projectiles will not travel as long a distance or penetrate walls like other firearms and possibly kill or injure family members, neighbors etc."
Wrong. A shotgun makes a great home defense weapon because of the power it has to incapacitate intruders quickly, not because it is harder to miss with one. A shorter barrel is preferable because it is more manueverable in tight places, not because it spreads the pattern. The "blunderbuss" barrel will destroy the shotgun's ability to penetrate deeply enough to incapacitate. It will make the shotgun effectively useless. You may as well get a coathanger and try to jab your attacker in the eye with it.
If you want proven home defense, get a simple eighteen inch barrel pump 12 gauge shotgun. Next, invest in training. Learn to use it well under all conditions and in tight places. Save the funnels for putting oil in your car. You can not make up for lack of training by sticking more bullshit on your gun. Software beats hardware every time.