This thing. Shipped to your door. Grandma and granddad already know how to use it because it's what they used back in the day.
Will put the fear of God into any unannounced visitors.
https://americanguncraft.com/product/diablo-break-open-12-gauge-pistol-black-grips/
Hmmm, have you ever heard of a fellow by the name of Newton? It seems like he came up with a third law that says "old people shooting something like that may wind as dead as the person in front of it."